Dan Margulis Applied Color Theory
Five Pressroom Tales of Horror
Those preparing files for commercial printing are often
counseled to "ask the printer" what separation settings to use,
on the theory that good printers should know such things. In the real
world, printers rarely do, often giving horrible advice that would result
in wrecked jobs. In late 2007, the following long thread appeared,
complaining about the information that one such printer had provided. In
the following three months, four similar complaints appeared about
different printers. Although not discussed at the same length as the first
case, they're worth a read.
—DM
I. Is the Printer's Profile Bad?
Printer profile bad?
Posted by: "Steve Peters"
Mon Oct 29, 2007 4:16 pm (PST)
I am preparing some RGB files to be printed on a cmyk
press in Hong Kong. These images are going to be used in "coffee
table" book. The printer has supplied me with a profile, but I am not
sure the profile is any good. It really flattens out the color, alot more
than the SWOP2006_Coated3v2 profile. The profile I was given is for an
offset press. I know this because the profile has "OffsetMatt" in
the name. I have an image that has a red of 253,39,31. When I convert with
the printers profile I get 0,72,75,0. When I convert using the SWOP profile
I get 0,97,83,0. I have a sample do the paper and it looks close to the
Epson proofing semi-matte, which is what I am going to use to proof on my
Epson 4800 with the Colorburst X-Proof rip. I have been trying to get in
touch with the printer, but I have only been able to speak with the
publisher. The publisher says that they have just used the standard swop
profile in the past and then supplied them with proofs for them to match.
But my concern is that when I convert with the printers profile I get a TIL
of 340. I am under a tight deadline and I am not sure if I can wait to get
more info. I don't really have to much more time to wait for an answer from
the printer. So what is the best way to proceed? Do I just use the swop
profile or do I create a custom cmyk setting using 20% dot gain and a TIL
340?
Thanks,
Steve Peters
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Tue Oct 30, 2007 4:10 am (PST)
Steve, I presume that the RGB space to assign to your
values is A98 (you did not say, not that it really matters in this case
though).
What rendering intent did you use that resulted in
72m75y for the red (the RGB values are out of gamut for common press
conditions). If perceptual, does relative colorimetric with BPC provide
better results? Perhaps try all four intents and see if one is better for
saturation, but still acceptable for TAC, black point scaling etc. Are you
using the Adobe ACE or another (MS ICM or Apple ColorSync)? Perhaps try a
different colour engine to see if results vary with this particular
profile. Obviously the SWOP and this printer are using different stock and
ink, but I would presume that one could do better for reds than what this
profile provides with your current conversion settings.
You mention, 340 TIL, but what is the K limit? If you
convert a 0r0g0b patch to CMYK, what shadow build do you get (it should
vary between render intents). What is the character of the K plate? What
GCR or UCR is going on for neutrals and colours? Where does K start, how
'steep' is the ramp from start to the K limit? Gray gradients and step
patch test files are handy for this evaluation.
You ask about simply converting with another profile.
Convert to say SWOP v2 and then assign the OffsetMatt to see what the image
would be like in this new condition (CMYK values remain the same). Or
better yet, perform a softproof with preserve values checked, instead of/in
addition to the assign step. Using a neutral step wedge, one can evaluate
neutrals via LAB readings to see what happens to the SWOP v2 gray balance
when it is used in the OffsetMatt condition.
Repeat and do the same for Custom CMYK too, to see how
this compares to the other two profiles.
Another thing to evaluate is dot gain/TVI. If you are
going to use SWOP v2 (TR001), does this printer in HK have similar dot gain
to the TR001 files that you may supply?
It is best to get the separations right to begin with,
but one can also edit the less than satisfactory CMYK file and make the
reds and or other hues or tones richer if desired. Unlike inkjet printing,
you are working in final print space and can thus directly control the
values (one is not forced to accept the profiles values).
Hope this helps,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: J Walton
Tue Oct 30, 2007 11:04 am (PST)
You've got a potentially troublesome situation on your
hands with this book. You can't get hold of the printer, but you do have a
profile that supposedly describes their press condition. The profile,
however, doesn't make a whole lot of sense.
Your client (I think), the publisher, tells you that in
the past they have not used the printer's profile and simply converted to
SWOP.
Is there any reason you *have to* supply CMYK to the
printer? If you can show your client what your images look like on an
industry-standard proof, and they are OK with the printer doing the
conversions and matching to your proofs on press, then if it doesn't look
good (like the proof) the blame will be on them.
If you take over a fundamental part of the printing
process and don't have a solid grasp on the kind of jargon that will get
thrown around after the job gets bounced you will be left holding the bag.
And it sounds like the printing will be expensive.
If it were me, I'd do everything I could to get in
touch with the printer and get a comfort level with their profile, or even
better, agree on something similar (like GRACOL or SWOP). No matter what
happens with that I'd have a frank conversation with my client, explaining
the potential problems, and getting them on the same page in the decision.
If you absolutely have to convert to something I'd say
do what the publisher told you, not the printer.
--
J Walton
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Steve Peters"
Tue Oct 30, 2007 8:01 pm (PST)
There was one other thing. I just tried converting that
same file using custom cmyk settings, swop (coated) 17%, gcr, light,K limit
85%, til 350. The red printed pretty flat with those settings as well, and
the proof and monitor are way off. I like the way the colors are
reproducing with the SWOP2006 profile and I am able to use soft proofing.
If I find out that I need to have a TIL of 340, what is the best way to go
about getting there? Could I just use the GRACoL2006_Coated1v2?
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Steve Peters"
Tue Oct 30, 2007 8:01 pm (PST)
Thanks guys. The rendering intent was relative with BPC
and I am using Adobe ACE. I did try other intents and rendering engines and
none where any better. I know that this could be a big problem and I have
been in contact with my client and they understand the issues.
So I have a 21 step white to black. Using the supplied
profile, 0,0,0 comes out to 88,80,84,91, so that actually 343. Black comes
in at the 166,166,166 which is 33,24,25,1.
I know that I really need to get more information from
the printer. 99% of the time my file are going to be printed in standard us
pubs, which I would usually use the latest SWOP2006_3v2 profile that I got
from SWOP.org. It's very rare that I have to actually deal with a printer,
but the times that I have they have never been able to give me any more
information that "convert to cmyk". Or if I am lucky they would
at least know the TIL or dot gain. So I am trying to at least get the TIl
and dot gain. The publisher has told me that they have just used the
standard swop profile with in photoshop and then supplied them with a
proof. But if the TIL is actually 340 and I give them files that are only
at 300%, and supply them with a cmyk proof from my Epson, will they be able
to match it? The reason we don't just give them the rgb files is because
there are alot of very bright saturated colors that will not reproduce so
we are going to need to make some artistic adjustments that we are not
comfortable letting some one else do. If I can at least get the TIL and dot
gain should I just create a custom cmyk setting? I am assuming that
soft-proofing with a custom cmyk setting is pretty much pointless? I do
know that the Colorburst X-Proof rip comes with Spectravision pro and I do
have the X-Rite pulse. Is there any way I could create a profile using the
Spectravision Pro software and use the TIL and dot gain of the actual
press? I know that this is only going to be profiling my printer and paper,
but it seems like there should be some way to make this work. Wouldn't I at
least get better soft proofing? Which in this case is kind of important so
that we aren't having to pull a bunch of proofs when we are trying to
adjust those out of gamut colors?
I know that I am still going to be taking a gamble with
all of this, but in lieu of getting all of the pertinent info, I have to
figure out the best way to minimize any issues.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Howard Smith
Wed Oct 31, 2007 2:30 am (PST)
While this sort of problem is out of my field, I can't
help but wonder what would happen if you sent an sRGB file along with a
proof print and ask the printer if he can give you a good match. If the
printer is so confident of his operation that he feels it unnecessary to
work with you, would it be unreasonable to expect him to convert your sRGB
file to the CMYK profile that produces a good match on his press under his
printing conditions? I would think that an sRGB image file that he converts
to his custom profile should be expected to give as good a print on his
press as one might expect if you sent it to a printer who uses a SWOP
profile for a press that uses SWOP. The RGB file would be the same in
either case. If you're not the printer, and you can't get any useable
answers, doesn't it become the printer's problem if he has to make the
conversion? If he is unable to convert the file himself with the
expectation of at least coming very close to your proof print, shouldn't
the publisher be aware of that?
Howard Smith
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Peter Figen"
Steve,
Have you tried Stephen's suggestion of converting to
the supplied proifle and assigning your swop profile to see just how
different they are tonally and color wise? That'll tell you a lot. If there
is a big shift when you assign your swop profile, then it'll be pretty
clear that your printer is not using something close to swop. You can't
judge how your colors are looking when you use the wrong profile - that is,
if the swop profile which you say makes your colors look good, is not
correct for your press, then it's just a waste of time. Better to use the
right profile and tweak the image after converting if that's what it takes.
Who's to say they're not using some non standard ink that needs different
percentages to make the colors you're after.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Wed Oct 31, 2007 4:50 am (PST)
Peter Figen wrote:
Have you tried Stephen's suggestion of converting to
the supplied
proifle and assigning your swop profile to see just how
different they
are tonally and color wise? That'll tell you a lot. If
there is a big
shift when you assign your swop profile, then it'll be
pretty clear
that your printer is not using something close to swop.
You can't
judge how your colors are looking when you use the
wrong profile -
that is, if the swop profile which you say makes your
colors look
good, is not correct for your press, then it's just a
waste of time.
Thanks Peter, this is one important aspect of
evaluation, although I suggested converting to SWOP v2 then assigning the
OffsetMatt profile/softproofing as this will indicate how the SWOP numbers
will reproduce in this new setting (if the profile is acceptable for this
soft-proofing or proofing task).
Better to use the right profile and tweak the image
after converting
if that's what it takes. Who's to say they're not using
some non
standard ink that needs different percentages to make
the colors
you're after.
I agree on the first sentence Peter, if using the
'false' SWOP conversion for the OffsetMatt condition and proofing is not
acceptable.
You could be correct about the inkset, but we are
talking of Adobe RGB values of r253 g39 b31, for all intents and purposes a
highly saturated red, out of press gamut (even in sRGB this is OoG for
typical press conditions). A sensible separation approach would deliver a
highly saturated result in CMYK. No matter what ink is used, one would want
to increase to full/near full MY with no or little CK values (in a flat
area that contains no detail).
Steve also reported that generally speaking, the images
are coming out rather flat and disappointing. These are probably the tricky
saturated images that he spoke of. It is unclear to me if more subdued
images within press gamut convert similar to the SWOP.org profile, or if
RGB colour within press gamut is weak too.
Having access to the profile would answer many of these
questions.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Wed Oct 31, 2007 4:53 am (PST)
Steve, as you may know - there is a lot of variability
in profiles that describe the same/similar condition.
Your Adobe RGB red hue values of:
253r 39g 31b
Convert to (RelCol+BPC):
SWOP TR001 Chromix - 80m 84y
SWOP Press - 91m 87y
SWOP v2 Adobe - 93m 85y
SWOP TR001 - 97m 100y
With Perceptual rendering, the Chromix profile really
washes out with a result of - 71m 74y.
So it may just be the profile and an update to the
profile creation software or another profile package or perhaps different
operator choices may produce a better profile for the same condition from
the same measurement data.
Reducing saturation before conversion for OoG hues may
be required to produce a 'richer' conversion.
You could try doing two conversions, one to the
OffsetMatt and one to SWOP...Layer the SWOP file over the OffsetMatt with
no conversion (retain values over appearance) - try setting the blending
mode to darken to compare to normal. In the advanced blending (layer)
blending options for the upper SWOP layer, uncheck the K channel check box
and perhaps use blend if sliders to blend in the darker values (so as not
to mess with gray balance in the light end of the tonal scale). One may
need to layer mask (saturation or density mask) this in key areas that
require a saturation boost. This can all be put into an action, although it
may just be easier to use selective colour to boost values in the red hues
etc. It will depend on the image if simple edits or blends of two
conversions or more work will be needed.
Hope this helps,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Laurentiu Todie"
Wed Oct 31, 2007 6:08 am (PST)
A SWOP printer would soot himself in the foot by having
files reduced to sRGB, a packaging (Hexachrome?) printer would aim higher.
On the Mac platform, open the Color Sync Utility
click on the Profiles icon (top bar)
chose sRGB
Control click on the color windowhold for comparison
chose US Sheetfed Coated v2
Observe that some of the CMYK colors fall outside the
sRGB space.
(that's the foot shot : )
Hexachrome is a larger space than CMYK
(that could be the higher target—the crotch? the
head? : )
Laurentiu Todie
__________________________________________________________________________
Re: Printer profile bad?
Posted by: "Peter Figen"
Wed Oct 31, 2007 8:59 am (PST)
On Oct 31, 2007, at 3:00 AM, Stephen Marsh wrote:
Having access to the profile would answer many of these
questions.
Absolutely. Too many profiles provided are also built
with ink limits, black generation or rendering options that suggest whoever
built the profile didn't understand the printing process. I will often dump
provided profiles back into ProfileMaker and rebuild them to suit, or pull
them into ProfileEditor and tweak specific response.
Peter Figen
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Steve Peters"
Wed Oct 31, 2007 1:07 pm (PST)
So I posted the profile in the files section of this
forum. The name
is Midas_KBA_OffsetMatt_V3.icm.zip
I still have no more printer info today and I need to
get started.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Wed Oct 31, 2007 9:27 pm (PST)
Steve, no time for a deep reply during my working
day...
My advice is to Convert to SWOP v2 or SWOP.org ICC
first, then go from SWOP to MattCoated.
Yes, that is right, RGB > CMYK and then CMYK >
CMYK (I have never had to do this for good press conditions, only
newsprint!).
I'll post more later if required, if the numbers and
preview do not make sense with this brief explanation!
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Howard Smith
Wed Oct 31, 2007 9:27 pm (PST)
Thanks, Laurentiu! All this time I thought (mistakenly)
that sRGB was the ideal space for conversion to CMYK when one wants to
reduce the color loss as much as possible. I've found that the service
bureaus with which I worked in the past all seemed to share this opinion.
I'll never forget one highly recommended "expert" looking down
his nose at me and sniffing that not many people know the right color space
for a scan when the final image is intended for CMYK printing (he was
convinced that sRGB was the obvious choice) . I'm sure others have covered
your points in print, but somehow it never made an impression. Probably
because I've not had any hands-on experience with CMYK printing other
than--long ago--working with a commercial printer's press supervisor to
make sure the output was close enough to the proofs prepared by others from
my 8 x 10 transparencies.
But a question lingers. Dan has repeatedly suggested
submitting an RGB image file (or a LAB image file) to a printer when there
is some question about which CMYK profile to use for conversion. Wouldn't
an Adobe RGB 1998 file go to the opposite extreme and give colors that
wouldn't convert well? I'm beginning to see why so many different solutions
are being provided in response to the original post. There don't see to be
any easy answers.
Howard Smith
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Laurentiu Todie"
Thu Nov 1, 2007 5:05 am (PST)
Truth be told, there aren't legions of CMYK colors
falling outside of the sRGB space. You'd have to be kind of greedy to want
pure cyan, "better" greens and bright yellow (I am : )
Besides, those colors are not visible on most monitors
(they are on paper) and as better (16bit) monitors become available, better
CMYK inksets seem to be made so we're chasing our tails.
The "expert" scanner technician may not be
aware of Plato's observation from 2500 years ago. which is that we can only
be experts in our own… cave : ) My cave is not that of a color
expert, and it is definitely smaller than say,… Stephen Hawking's
who's range of expertise goes from neutrinos to black holes, but I'd give
the offset printer a file in the "capture space" (unless the edit
space is larger and some of it's additional colors were obtained through
curves or other means) This of course means that the capture was not done
by one of NASA's super scanners and that the edit was done by an expert who
didn't trade shape for saturation.
At times like this I wish that Bruce Fraser was still
around, not because his cave was larger, but more focused and his command
of the English language was kicking the ass of my Romanglish (Romanian
native—American by choice)
PS
I (personally) would give the offset printer a
converted (to his space) file with a black plate who's deep SD was extended
to close to 98% if needed, but printers are jealous of their spaces or
don't know their cave to save their own lives or think that we are stupid :
) Well,.. some of us are as some of them are too.
Laurentiu Todie
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Thu Nov 1, 2007 5:05 am (PST)
Further to my earlier reply -
Steve, now that I have had time, I can make some
observations on this Midas profile and then I will comment on the
conversion workflow.
It appears that this profile has major problems
converting highly saturated red and green hues, such as found in the
primaries of common RGB working spaces (and the opposing hues cyan and
magenta). Blues (and the opposing hue yellow) are "better" for
some unknown reason. The profile does not appear to have issues with
in-gamut colours and provides similar results to other common profiles.
Rendering intents - relative colorimetric with black
point compensation seems to be the best choice, particularly so for out of
gamut reds and greens. If one wishes to depart from the original RGB
slightly, one can use the perceptual intent, although this is not
recommended for saturated originals.
As my previous brief post indicated, after testing the
profile I now strongly recommend that you convert highly saturated images
that have problems with a regular conversion workflow using my suggested
two-step workflow approach. You may wish to just convert all images with
this two-step conversion workflow, just for consistent results and to
simplify things (you will obviously be working on dupes and will have
access to the RGB files if you need to reconvert or channel blend a tricky
file).
1. Convert from RGB to Adobe U.S. Web Coated SWOP v2
(TR001). You will likely use RelCol+BPC in this step, although the
conservative/subtle gamut compression offered by the Adobe profiles
perceptual intent may help if there is detail in highly saturated areas of
the RGB file.
2. Once the file is in CMYK, do a second conversion to
the Midas CMYK profile using RelCol+BPC. The previous conversion to a
"well behaved" press profile will have tamed the out of gamut
colours, thus not leaving you to the mercy of the Midas profile's handling
of OoG colours. The Midas profile will have no problems converting from the
more similar TR001 press space than say direct from Adobe RGB. You will now
have saturation similar to that offered by other profiles.
This would be put into an action. It would then be your
choice on how you would use this action. One may simply automate>batch
the action, for attended or unattended conversion and saving of all the
source files.
One would then inspect all the conversions and perhaps
tweak some of the images. Special cases may require converting via
perceptual intent with a *non* Adobe CMYK profile (less conservative) in
step 1, before converting to the Midas profile in step 2 and then
performing post conversion edits (curves, channel blends etc).
As an earlier post of mine indicated, reducing
saturation in the OoG RGB hues before converting to the Midas profile would
create more pleasing results. I find that converting to a
"better" intermediate CMYK profile is a faster process and
provides better results than say reducing saturation via the hue/saturation
command slider (normal or color blend) or with AB curves in LAB.
I hope the rest of your project runs smoother than the
CMYK conversion process!
Regards,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Laurentiu Todie"
Thu Nov 1, 2007 6:18 am (PST)
Sorry about this "vanity" post : )
On Nov 1, 2007, at 5:27 AM, Laurentiu Todie wrote:
(unless the edit space is larger and some of it's
additional colors
were obtained through curves or other means)
"it's" is a typo
At times like this I wish that Bruce Fraser was still
around, not because his cave was larger, but more focused and his command
of the English language was kicking the ass of my Romanglish (Romanian
native—American by choice)
The forum software seems to have removed my (em?)
hyphen should read: "Romanian native, American by choice"
and for Dan (who banned me for sarcasm, in the past)
the language barrier can lead to frustration, frustration can lead to
sarcasm well,.. that's my explanation/excuse : )
Laurentiu Todie
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Thu Nov 1, 2007 7:45 am (PST)
On Oct 31, 2007, at 8:10 AM, Laurentiu Todie wrote:
A SWOP printer would soot himself in the foot by having
files reduced
to sRGB,
Huh? sRGB would actually work fine for SWOP. The only
areas where SWOP is actually out-of-gamut compared to sRGB is in a small
portion of pure cyans. Otherwise, sRGB works fine for conversion to many
typical CMYK press color spaces. Not true of course for typical CMYK inkjet
gamuts. AdobeRGB is better suited for full-gamut inkjet printing.
Hexachrome is a larger space than CMYK
(that could be the higher target—the crotch? the
head?
Not necessarily. Any decent (good media) CMYK inkjet
profile is going to be larger than Hexachrome. Even if you're talking
"press" CMYK spaces, it's not a given that Hex is larger since
there are several "wide-gamut" CMYK ink sets designed for offset
printing.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Thu Nov 1, 2007 9:50 am (PST)
Steve, here's what I can tell you about your
profile....
* Total ink limit is closer to 350% (348% to be
precise) with a K limit of 95%. This is way too high of a TIL in my
opinion. Like I said earlier, with a K limit of 100%, you really don't need
more than about 280-300% TIL to achieve maximum printable density.
* Profile was made using Agfa ColorTune. I can't say
one way or another if this is a good profiling application or not but I can
tell you that NONE of my colleagues use this application.
* Precision is probably not very good. This profile
only uses 9 grid points in the A2B table and only 17 grid points in the B2A
(separation) table. Most profiles will use at least 25-33 grid points for
the separation table.
* Probably the most disturbing things about the profile
showed up when I viewed the hue/chroma plot. In comparison to
SWOP2006_Coated3, I observed the following:
* Cyan is "weak" (lacking in chroma) and has
a fairly large shift towards blue/magenta. I would call this a very
"dirty" cyan.
* Magenta is slighty weak but the hue is OK.
* Yellow has good chroma/saturation but the hue is
slightly shifted towards green.
* Blue (C+M) is a bit too saturated but is very
"purple" or magenta casted probably due to magenta contamination
of the cyan ink. Bottom line, if you were touse the SWOP2006_Coated3
profile to separate with, you'll end up with purple blues on press, if they
print like this profile predicts. The relatively high chroma of the blue
has me wondering whether this came from an actual offset press or did it
come from a dot proofer such as a Kodak Approval? I've seen both dirty
cyans and too-magenta blues with particular "ink sets" on
Approvals. Dot proofers with their perfect "wet trap"
characteristics will generally show a higher blue chroma compared to an
actual press plus a hue shift towards magenta.
* Red (M+Y) is fine as far as hue angle but is a bit
weak in chroma.
* Green (C+Y) at 100% is fine for both hue and chroma
but has a yellow hue shift between 60-80%.
* The GOOD news about this profile is the gray balance
characteristics. At the midtone, it's within 2-3% of standard GRACoL/ SWOP
gray balance but it does get a bit worse in the 3/4 tones. If you separated
using SWOP2006_Coated3 and printed on this "press", you'd see a
decidely warm/reddish cast in the neutrals assuming, again, that the press
prints like your profile predicts.
As to your problems when using this profile to
separate, I believe that it's an issue of rendering intents. If you're
using perceptual, there can be a HUGE difference in how different profiling
applications convert using this intent. Monaco PROFILER is typically the
"best" in terms of it's perceptual rendering but ProfileMaker is
pretty decent also. I have not idea how an Agfa ColorTune profile behaves
using different rendering intents.
Steve, I'm uploading a new profile as we speak for you
to try. It's build using ProfileMaker. The name is
"Midas_KBA_OffsetMatt_TIL320.icc.zip". Give
it a try.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Laurentiu Todie"
Thu Nov 1, 2007 9:50 am (PST)
On Nov 1, 2007, at 10:43 AM, Terry Wyse wrote:
Not necessarily. Any decent (good media) CMYK inkjet
profile is going
to be larger than Hexachrome. Even if you're talking
"press" CMYK
spaces, it's not a given that Hex is larger since there
are several
"wide-gamut" CMYK ink sets designed for
offset printing.
…none of which print Orange.
Look, I'm just giving the gist of color spaces, the way
I see it. A loss is a loss, and sRGB won't do for me. You can do what you
want.
Laurentiu Todie
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Peter Figen"
Thu Nov 1, 2007 9:50 am (PST)
I just looked at Steve's Midas profile this morning.
Overall, it's pretty close to SWOPv2 in its basic look. The saturated red
thing is definitely a problem, so I used ColorLab to build a data file
(this was an Agfa profile that had no embedded measurement data) and then
imported the new measurement data into ProfileMaker and built a new profile
that has much better red rendering. I sent the new version directly to
Steve. The whole process took about three minutes.
Peter Figen
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Dan Margulis
Mon Nov 5, 2007 5:55 am (PST)
Just to reemphasize Stephen's point, there are three
important lessons to be drawn from this instructive thread.
1) When you ask a profile to convert something that's
as wildly out of printer gamut as this particular red is, you're playing
Russian roulette. There isn't any "right" way to handle this
situation because the color being demanded is far, far, too intense for the
printer to handle. To get an in-gamut color from this extremely intense
light red, you'd have to, if using Hue/Saturation, take saturation down to
-50 or so.
In such cases the only question is not whether a
horrible mismatch can be avoided, but which horrible mismatch is the least
objectionable. That will depend on the image. If there's a fire engine or a
Canadian flag in the picture, which would both be in the 100m100y range,
then the SWOPTR001 rendition of the lighter red would be a big mistake,
because we wouldn't be able to tell these highly dissimilar colors apart.
OTOH, the more ink being used, the more intense the color. If there aren't
any competing reds, then the SWOPTR001 lie is probably the preferable one:
better a relatively bright red that's too dark, than one that's the right
weight but too dull.
In evaluating a profile's performance, then, colors
like these are best ignored, because there isn't any right answer.
Concentrate on ones that the printer has some remote possibility of
hitting.
2) I haven't looked at the profile myself, but Terry,
Stephen, and Peter all seem to find fault with it. If so, it's no surprise.
Profiles handed out by commercial printers are like stock market tips
handed out by printers. If you have some evidence that the printer knows
WTF he's talking about, then his profiles and stock market tips are both to
be given some respect. But an unknown printer--I wouldn't assume that the
profile was worth anything. Which is a a very strong argument for those who
may find themselves at a printer's mercy to learn enough about the process
so that that lamentable situation is avoided in the future.
3) Both Peter and Terry report that they were able to
generate corrected profiles in short order. That serious professionals find
it necessary to edit CMYK profiles in real-world contexts like this one is
a strong argument for the inclusion of profile editing in Photoshop.
My thanks to those who contributed to this good thread.
Dan Margulis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Tue Nov 6, 2007 4:24 am (PST)
On Nov 4, 2007, at 7:52 PM, Dan Margulis wrote:
3) Both Peter and Terry report that they were able to
generate
corrected profiles in short order. That serious
professionals find it
necessary to edit CMYK profiles in real-world contexts
like this
one is a strong argument for the inclusion of profile
editing in Photoshop.
No, if you carefully read what Terry wrote, he
"built" a new profile "using ProfileMaker." He further
noted that not all profiling applications give equivalent results
(particularly with perceptual rendering intents), and that the profile
generation software (Agfa ColorTune) used to generate the printer's profile
is generally not used in the industry and that it is in that respect an
"unknown." He also noted that the ColorTune profile uses only
9/17 (vs 17/33) LUT grid points. X-Rite's ProfileMaker and Monaco PROFILER
are the runaway favorites for profile generation. But in general, most
experts agree that it is much better to generate a new profile than it is
to try to edit a profile. My preference is ProfileMaker, but I've spent
very little time with PROFILER.
Rather than an argument that Adobe should bundle a
profiling editing application within Photoshop, this thread makes the point
that good tools are already available, and they can be purchased (like
Photoshop) by those who need to use them. (That should have included the
printer!) Of course, one also needs to know *how* to use these specialized
tools (or hire a consultant). And if you don't own a spectrophotometer, you
won't be generating many profiles, regardless of what software you use, or
whether or not it's bundled with Photoshop. Profiling is all about
colorimetry, plain and simple. Good profiles are the answer. A bunch of
hacked (and deceptively modified / named) profiles is not. If you want to
edit or create profiles, there is already good software available. Asking
Adobe to bundle equivalent software is not reasonable. These are full-blown
applications. And if you do much profile generation / evaluation, you
should also have Steve Upton's ColorThink Pro to examine and evaluate the
profiles.
Perhaps Terry could shed some light on how he evaluated
the bad profile and how he built the new one.
--Rich Wagner
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Tue Nov 6, 2007 4:24 am (PST)
Peter Figen wrote:
I just looked at Steve's Midas profile this morning.
Overall, it's
pretty close to SWOPv2 in its basic look.
Peter, I don't have the hardware or 'proper' software,
so my evaluations are usually performed in Photoshop with RGB and CMYK test
images. I can compare the gamut in 3D in WinXP and also look at a gamut
plot in ColorSync on the Mac. On the PC, I can also use two free apps -
"ICC Profile Inspector" and "ICC Inspect" to find out
some basic under the hood details on profiles.
There are 17 tags listed (starting from #0), with tag
#8 with a signature of DMDD or Device Model Description tag. This is listed
as "Euro Standard". Go figure. PCS=LAB, Default Intent=RelCol.
The saturated red thing is
definitely a problem, so I used ColorLab to build a
data file (this
was an Agfa profile that had no embedded measurement
data) and then
imported the new measurement data into ProfileMaker and
built a new
profile that has much better red rendering. I sent the
new version
directly to Steve. The whole process took about three
minutes.
I suspect that if there is any measurement data, it is
hidden away in tag #3 with a signature of AGFA. This is a private or
unknown tag. It shows that an IT8.7.3 was used with an Xrite DTP41 with
Agfa ColorTune Pro 4.2.1 Mac OS Classic. This tag is huge, larger than any
of the A2xx or B2xx tags.
Tag #16 has a signature of VUED or Viewing Condition
Description Tag, which lists what appear to be some sort of reference to
measurement data in the header which may mean nothing (nm380, nm390 etc).
It also states a TIL of 350%, K limit of 95% and K start of 30%.
As I only had access to Photoshop, I found great
results with converting to Adobe SWOP v2 first, then from SWOP to Midas
(RGB>CMYK, CMYK>CMYK). This still leaves one at the mercy of this
profile for TIL etc, but it cures the saturation issue for out of gamut
reds/greens as it has no problems with in gamut colour (despite it's other
problems).
Regards,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Tue Nov 6, 2007 11:41 am (PST)
Thank you for the in-depth reply Terry.
* Total ink limit is closer to 350% (348% to be
precise) with a K
limit of 95%. This is way too high of a TIL in my
opinion. Like I said
earlier, with a K limit of 100%, you really don't need
more than about
280-300% TIL to achieve maximum printable density.
I agree with you on the TIL Terry, as the profile
defaults to 95% K.
* Precision is probably not very good. This profile
only uses 9 grid
points in the A2B table and only 17 grid points in the
B2A
(separation) table. Most profiles will use at least
25-33 grid points
for the separation table.
For comparison, I looked at the Adobe SWOP v2 profile,
which uses a CLUT resolution A=9 and B=33. The Quark Xpress 6.5 SWOP TR001
profile uses A=17 and B=33. Chromix SWOP TR001 uses A=11 B=25.
* Probably the most disturbing things about the profile
showed up when
I viewed the hue/chroma plot. In comparison to
SWOP2006_Coated3, I
observed the following:
* Cyan is "weak" (lacking in chroma) and has
a fairly large shift
towards blue/magenta. I would call this a very
"dirty" cyan.
Can you expand on this point Terry? I only used
Photoshop to evaluate the ink:
Adobe SWOP v2 Cyan 100% = 62L -44A -50B
Midas Offset Matt Cyan 100% = 56L -29A -49B
I presume that you are referring to the differences in
the L and A values (not that TR001 is an "ideal" reference or the
exact condition that Midas may use, but it makes a good general yardstick
for comparison).
Side note: I had RelCol set in my Color Settings when
performing the above evaluations, a more "accurate" evaluation
could perhaps be obtained by temporarily setting the rendering intent to
AbsCol before performing info palette evaluations of single solids, tints
and overprints of CMYK values.
The relatively high chroma of the blue has me
wondering whether this came from an actual offset press
or did it come
from a dot proofer such as a Kodak Approval?
The Device Model Description tag states "Euro
Standard", for what this is worth.
As to your problems when using this profile to
separate, I believe
that it's an issue of rendering intents. If you're
using perceptual,
there can be a HUGE difference in how different
profiling applications
convert using this intent.
I asked this of Steve earlier and he said that RelCol
was being used, although all intents were tried will similar results.
Something deeper is going on here Terry. It appears
that this profile simply falls apart when presented a wildly out of gamut
colour. The results for in-gamut colour are similar to other profiles.
Steve's A98 red of 253r 39g 31b converts to Midas CMYK:
Perceptual/Image = 75m83y
Relative Colorimetric + BPC = 72m75y
Compared to RelCol+BPC:
SWOP TR001 Chromix - 80m 84y
SWOP Press - 91m 87y
SWOP v2 Adobe - 93m 85y
SWOP TR001 - 97m 100y
Your adjusted/recreated profile with the 320% TIL
converts to:
Perceptual rendering intent = 88m73y
Relative Colorimetric + Black Point Compensation =
91m95y
It is not just OoG red hues that are improved, green is
better and so is blue (you appear to have been conservative with the ratio
of magenta to cyan in OoG blues, which I applaud).
As I only have Photoshop, my hack was to first convert
from A98 RGB to Adobe SWOP v2, then from SWOP v2 to the Midas Offset Coated
profile. This resulted in the red hue discussed above converting to:
90m88y1k
The low K tones introduced are not ideal, but can
easily be removed with selective colour, or a curve without affecting the
quarter tones or higher or any true K plate content (with the start point
being 30 on the grey ramp). This provides better results than RGB to Midas
CMYK if one does not have access to dedicated profile software.
Steve, I'm uploading a new profile as we speak for you
to try. It's
build using ProfileMaker. The name is
"Midas_KBA_OffsetMatt_TIL320.icc.zip". Give
it a try.
Terry, thank you for the illustration of the difference
between software and operators and how this affects a given profile for the
same condition.
P.S. If you are up for some limited talk on v4 profiles
(and how the ICC now seem to state how profiles should be used [not so
simple!]), perceptual rendering and "preferential" conversion
aspects of profiles, particularly in regards to CMYK perceptual transforms
- then I for one would be interested in such a discussion.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Tue Nov 6, 2007 11:42 am (PST)
On Nov 5, 2007, at 2:43 PM, Richard Wagner wrote:
Perhaps Terry could shed some light on how he evaluated
the bad
profile and how he built the new one.
I cheated, that's how! :-)
Actually, I'm a little embarrassed that Richard pointed
out something that I simply left slide by; the fact that I *did not* edit
the profile in question but I in fact built an entirely new profile from
the colorimetric data of the original profile. With the exception of
Photoshop's "Custom" CMYK engine, there's no real profile editing
applications that I know of that can take a profile and re-generate it's
separation settings. Neither Monaco's built-in profile editor nor
ProfileMaker's Profile Editor app has any features to change the GCR, total
ink limit, etc. To do THAT you need to build a new profile.
As far as what I used to evaluate Steve's profile, I
used the following:
ColorThink Pro 3.0 by Steve Upton at Chromix, the
"swiss army knife" of profile evaluation apps. I used Colorthink
primarily to view all the tags in the profile, looking for a tag that MIGHT
have had the original colorimetry (measurement data) that I could extract
and use to build the new profile (alas, it did not). I also used ColorThink
Pro to evaluate and compare the gamut plots between Steve's profile and
SWOP2006_Coated3 (note to all folks on this forum, "SWOPv2" is
NOT the official SWOP profile anymore, hasn't been for over a year now,
it's the new "G7" SWOP2006 profiles that are the official
"blessed" ones these days). Also note that a typical gamut plot
display the "volume" of a profile is not all that telling. What I
was able to do in ColorThink Pro is look at the hue/chroma plot of the
primaries and secondaries which showed that, contrary to some statements,
this profile was nothing like SWOPv2, especially in the cyans/blues. The
gamut plot might have been similar looking (most "press" CMYK
profiles look similar in that regard) but that doesn't always reveal what's
going on with the primaries/secondaries.
The other profile evaluation program I turn to is
ColorShop X by Chris Halford at X-Rite. I generally use this for a second
look at the primaries/secondaries since this app allows you to look at the
different rendering intents. For evaluating a profiles
"separation" characteristics, looking at the relative and
perceptual rendering intents is more telling that using absolute
colorimetry. I also use ColorShop X to evaluate the gray balance and K
generation settings. With their "Neutral Analysis" plot, you can
look at the CMY gray balance, view the K start and K limit, and also look
at the "stability" or accuracy of the gray balance in the
profile.
Getting to back to how I was able to actually build a
new profile, the way I did it was to use the LOGO ColorLab application to
"extract" the measurment data from the profile. I did this by
opening up a text reference file of an IT8.7/4 chart and converted this to
LAB and saved this as a text file of the original measurements. This is far
from an ideal way to do this because I'm relying on the inherent accuracy
of the original profile's (already suspect in my view) CMYK-to-Lab (A2B)
conversion. Once I had the Lab data, it was a simple matter to import this
into ProfileMaker and build the new profile (bonus points to anybody that
knows of an easier way (there is) I could've done the same thing).
To Richard's point, we don't need no friggin' new
profile editor/creator as part of Photoshop; the program is already bloated
enough in my view. As a color management consultant, I also don't want to
see even more poorly built profiles floating out there in the ether because
of a possible half-baked attempt by Adobe. It's taken us this long (10+
years) to get to the point we're at today in terms of having really good
measurement instruments and profile creation/editing/ evaluation
applications and we're still not QUITE there yet in my opinion. I'd hate to
see us take a few steps backwards.
Now, back to the Funny Farm,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Tue Nov 6, 2007 11:42 am (PST)
Peter Figen is correct - there is no measurement data
embedded within the Agfa profile, which is why he used ColorLab to build a
(synthetic) datafile from the profile, and then used ProfileMaker (as did
Terry Wyse) to build a new profile. Note that neither Terry nor Peter
"edited" the existing profile, even though ProfileMaker 5
includes a separate profile-editing program that they both had access to,
creatively named ProfileEditor.
The private tag named "agfa" of type
"data" cannot be read outside of ColorTune, and I have no idea
what the data is used for. Agfa notes that "ColorTune Pro uses
ICC-based profiles and unique mathematical algorithms to calibrate each of
your output devices. Then, it uses the device characterization within each
profile to automatically compensate for differences in color ranges between
your monitor, printer, proofer and printing press." As the tag
contains proprietary data, all bets are off. If you look in ProfileMaker
profiles (like the one Terry posted), the data sets are stored in ASCII
text. This makes it easy to open and re-build profiles using different
parameters, or to examine the original measurement data.
--Rich Wagner
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Peter Figen"
Tue Nov 6, 2007 11:42 am (PST)
Can't speak exactly for Terry, but I'm pretty sure he
used the same tools I did. Since the Midas profile had no measurement data
included in the profile itself, I used Gretag's free but unsupported
ColorLab program to generate a new set of measurement data. It works
basically by loading the text data from a standard CMYK profiling target
and then converting that information to Lab using the Midas profile and
Absolute Colorimetric rendering. ColorLab will then save out a new set of
measurement data based on that conversion. While it's not exactly the same
as using the original measurements, it seems to be so close as to be
inconsequential. From there it's a simple matter to import that data back
into ProfileMaker and generate a new profile with whatever ink limits and
black generation you desire.
I don't bemoan the fact that these tools are not
included in Photoshop. As an imaging professional, I just see owning a good
spectro and a good profiling application are part of the basic toolkit.
Yeah, there is a certain price to it all, but it also give you a
competitive advantage that a lot of others do not have.
Peter Figen
www.peterfigen.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terence Wyse"
Tue Nov 6, 2007 3:13 pm (PST)
Comments in-line...
On Tuesday, November 06, 2007, at 02:44PM, "Peter
Figen" wrote:
Can't speak exactly for Terry, but I'm pretty sure he
used the same
tools I did. Since the Midas profile had no measurement
data included
in the profile itself, I used Gretag's free but
unsupported ColorLab
program to generate a new set of measurement data. It
works basically
by loading the text data from a standard CMYK profiling
target and
then converting that information to Lab using the Midas
profile and
Absolute Colorimetric rendering. ColorLab will then
save out a new
set of measurement data based on that conversion. While
it's not
exactly the same as using the original measurements, it
seems to be
so close as to be inconsequential. From there it's a
siimple matter
to import that data back into ProfileMaker and generate
a new profile
with whatever ink limits and black generation you
desire.
That's precisely how I did it (great minds think
alike?!).
In terms of accuracy, there can be a bit of comprising
of the "measurement" data when you convert using this method.
Depending on the originator (author?) of the profile, it can be upwards of
.25 dE. Doesn't sound like much but if you're using this method in a
proofing environment, that level of compromise can be unacceptable because
you have to assume the proofing system will compromise things even further.
Before you know it, you've got a real 3 dE mess on your hands! :-)
As far as the Agfa ColorTune profile, I would expect an
even higher degree of inaccuracy due to the lack of grid points in the A2B
side of the profile.
I don't bemoan the fact that these tools are not
included in
Photoshop. As an imaging professional, I just see
owning a good
spectro and a good profiling application are part of
the basic
toolkit. Yeah, there is a certain price to it all, but
it also give
you a competitive advantage that a lot of others do not
have.
Agree with that 110% Peter.
Regards,
Terry wyse
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terence Wyse"
Tue Nov 6, 2007 3:15 pm (PST)
Comments in-line...
On Tuesday, November 06, 2007, at 02:41PM,
"Stephen Marsh" wrote:
For comparison, I looked at the Adobe SWOP v2 profile,
which uses a
CLUT resolution A=9 and B=33. The Quark Xpress 6.5 SWOP
TR001 profile
uses A=17 and B=33. Chromix SWOP TR001 uses A=11 B=25.
Last I checked, both Monaco PROFILER and ProfileMaker
use 17 grid points max on the A2B side (CMYK-to-Lab). In the other
direction, B2A, Monaco defaults to 33 grid points but it's user selectable.
ProfileMaker defaults to 25 ("Large Profile") but I think will
drop to 17. Not sure on that because I always use the largest number of
grid points for accuracy.
Can you expand on this point Terry? I only used
Photoshop to evaluate
the ink:
Adobe SWOP v2 Cyan 100% = 62L -44A -50B
Midas Offset Matt Cyan 100% = 56L -29A -49B
I presume that you are referring to the differences in
the L and A
values (not that TR001 is an "ideal"
reference or the exact condition
that Midas may use, but it makes a good general
yardstick for comparison).
Yes, mostly the a* value. It's lower than the SWOP a*,
indicating that the ink is heading in the direction of magenta. The L* is
also telling us it's darker than SWOP, hence the "darker, dirtier and
too purple" comment.
I'd bet dollars-to-doughnuts that the profile came from
a Kodak Approval running Euro cyan material. Seen it before.
Side note: I had RelCol set in my Color Settings when
performing the
above evaluations, a more "accurate"
evaluation could perhaps be
obtained by temporarily setting the rendering intent to
AbsCol before
performing info palette evaluations of single solids,
tints and
overprints of CMYK values.
I usually default to using absolute since I'm usually
evaluating the profile relative to proofing but using relative is a
worthwhile excercise if you're primarily interested in how the profile
performs for separations.
Something deeper is going on here Terry. It appears
that this profile
simply falls apart when presented a wildly out of gamut
colour. The
results for in-gamut colour are similar to other
profiles.
I'll confess that I didn't even bother looking at the
actual numbers it produced going from RGB-to-CMYK. The fact that the
perceptual rendering produceds something wildly different than other
profiles doesn't surprise me but the relative+BPC numbers kind of surprise.
USUALLY you see more consistent behavior with that intent regardless of
where the profiles came from.
Your adjusted/recreated profile with the 320% TIL
converts to:
Perceptual rendering intent = 88m73y
Relative Colorimetric + Black Point Compensation =
91m95y
It is not just OoG red hues that are improved, green is
better and so
is blue (you appear to have been conservative with the
ratio of
magenta to cyan in OoG blues, which I applaud).
I'd love to take some credit but since I didn't *edit*
the profile in any way, the credit goes to ProfileMaker and their
"Colorful" gamut mapping option. Personally, my first choice
would've been to use Monaco PROFILER but I would've had to jump through a
few more hoops to make that happen.
Terry, thank you for the illustration of the difference
between
software and operators and how this affects a given
profile for the
same condition.
Happy to. Beats listening to the personal wrangling
that's gone on in recent months. I was THIS CLOSE to leaving this
contentious list a couple of months ago. It's "fun" having a
constructive thread for a change where I almost have something to
contribute.
P.S. If you are up for some limited talk on v4 profiles
(and how the
ICC now seem to state how profiles should be used [not
so simple!]),
perceptual rendering and "preferential"
conversion aspects of
profiles, particularly in regards to CMYK perceptual
transforms - then
I for one would be interested in such a discussion.
Eek. I can barely spell "v4 ICC profiles" let
alone speak with any kind of authority on the subject. I've been mostly
using v2 profiles only because many of the front-end RIP systems and
proofing systems I have to deal with haven't been able to handle v4
profiles reliably. Ya stick with what works in my line of work. Having said
that, I need to educate myself on v4 profiles and see if they offer any
advantages in my work. Somebody smarter than I can pick up the "v4
ICC" discussion gauntlet and possibly educate us all!
Regards,
Terry
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Wed Nov 7, 2007 10:40 am (PST)
On Nov 6, 2007, at 1:40 PM, Terence Wyse wrote:
Last I checked, both Monaco PROFILER and ProfileMaker
use 17 grid
points max on the A2B side (CMYK-to-Lab). In the other
direction,
B2A, Monaco defaults to 33 grid points but it's user
selectable.
ProfileMaker defaults to 25 ("Large Profile")
but I think will drop
to 17. Not sure on that because I always use the
largest number of
grid points for accuracy.
OK, you made me go back and check and build profiles
with each, because I was sure ProfileMaker used 33 grid points for large.
It goes like this with ProfileMaker:
"Default" = 11/25 grid points (A2B / B2A)
"Large" = 17 / 33 grid points (A2B / B2A)
I have always used Large as well. (The profile you
uploaded does in fact use 17/33.) I don't own Monaco PROFILER, so I can't
say what it uses.
--Rich Wagner
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Bret Hesler"
Wed Nov 7, 2007 10:41 am (PST)
I'll take those bonus points if nobody beat me to it.
In Profilemaker you can pick your favorite profiling chart in the Reference
Data drop down and then in the Measurement Data drop down, the second
selection is "Import ICC Profile..."
I usually work with Monaco Profiler, so I don't know if
you can then get the measurement
data out of the Profilemaker profile.
--
Bret Hesler
L.P. Thebault Company
Parsippany, New Jersey
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Peter Figen"
Wed Nov 7, 2007 7:50 pm (PST)
On Nov 7, 2007, at 5:06 AM, Bret Hesler wrote:
I'll take those bonus points if nobody beat me to it.
In
Profilemaker you can pick your favorite
profiling chart in the Reference Data drop down and
then in the
Measurement Data drop
down, the second selection is "Import ICC
Profile..."
I usually work with Monaco Profiler, so I don't know if
you can
then get the measurement
data out of the Profilemaker profile.
You can only do that if the profile you are importing
has the requisite data embedded in the profile. I tried that with the Agfa
generated Midas profile and came up with a missing tag error message. You
get the same result with PrintOpen profiles.
Peter
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Dan Margulis
Fri Nov 9, 2007 8:35 am (PST)
Terry writes,
we don't need no friggin' new profile editor/creator as
part of Photoshop;
the program is already bloated enough in
my view. As a color management consultant...
Certainly as a color management consultant it seems
undesirable for the general public to be able to edit existing profiles
without the aid of a color management consultant. Similarly, portrait
photographers used to believe that eliminating negatives was a bad idea
because it seemed to them undesirable for the general public to be able to
reprint existing work without the aid of a photographer. Prepress houses
thought that Macintoshes were a bad idea because it seemed to them
undesirable for the general public to be able to modify their own projects
without the aid of a prepress house.
Even today, at the Javits Center in New York, somewhat
restrictive rules exist because it seems undesirable to certain parties
that anything should be plugged into an electric outlet without the aid of
an electrician and an electrician's assistant.
...I also don't want to see
even more poorly built profiles floating out there in
the ether
because of a possible half-baked attempt by Adobe.
Wait a minute. This particular PBP was generated
without Adobe's assistance, no? It was causing a major problem in a paying
job, right? It was editable in three minutes, right? The new SWOP profiles
that you were recently recommending replaced PBPs with certain
well-documented peculiarities/defects, right? Given the prevalence of PBPs,
and their ability to mess up paid work, and the ease of repairing them in
three minutes or so, is it all that unreasonable to want to do it without
spending $2,500 or hiring an electrician (er, color management consultant)?
Saying that you don't want users to be able to modify
PBPs because you're afraid somebody may make them even worse is like me
advocating take curves out of Photoshop because so many people
color-correct badly with them. Having these capabilities do NOT make it
worse than it is in their absence.
To be sure, many people correct badly using curves. No
matter how incompetent the execution, however, they almost always make the
picture look better. Because even the incompetent know to do a Command-Z
after they apply curves, and if they don't think they made the picture
better, they conclude that they've wasted their time and they stick with
the original. And if they *do* think they've made the picture better, it
really doesn't matter what a professional retoucher thinks.
Similarly, if a person is sophisticated enough to
believe that a certain PBP has a problem that he feels competent to attempt
to fix, it is highly unlikely that the resulting new profile will be worse
than the original. Because if the person making it doesn't think it's
better afterward, he will conclude that he has wasted his time and goes
back to using the original PBP. And if he *does* think it's better, it
really doesn't matter what a color management consultant thinks.
It's taken us this long (10+ years) to get to the point
we're at today
I certainly agree that progress in the field has been
glacial, just as I predicted it would be in 1998, unless it became possible
for CMYK professionals to alter canned profiles for things like black
generation, dot gain, total ink, and minor color changes, without spending
$2,500 or hiring a color management consultant. So, yes. There has been
significant progress over the last ten years--probably so much so that we
have now reached the point we would have been at in Y2K had rudimentary
profile editing been a part of Photoshop from 1998 onward.
Because color management consultants have been, shall
we say, slow to grasp that they probably benefit more from the wide
availability of profile editing than any other group, they have been
reluctant to raise their voices to demand that Adobe make the trivial
programming effort needed to include a rudimentary CMYK profile editor in
Photoshop. If that reluctance continues, it can confidently be predicted
that progress will continue--and that by, say, 2050, we'll be where we
should have been in 2007.
Dan Margulis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Henry"
Fri Nov 9, 2007 2:10 pm (PST)
On Nov 6, 2007, at 3:12 PM, Terence Wyse wrote:
In terms of accuracy, there can be a bit of comprising
of the
"measurement" data when you convert using
this method. Depending on
the originator (author?) of the profile, it can be
upwards of .25
dE. Doesn't sound like much but if you're using this
method in a
proofing environment, that level of compromise can be
unacceptable
because you have to assume the proofing system will
compromise
things even further. Before you know it, you've got a
real 3 dE
mess on your hands! :-)
.25dE?
3dE mess?
I can appreciate the desire for precision, but for me
comments like this have forever insinuated a level of precision that is
unrealistic to expect on-press, real world.
Henry Davis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Fri Nov 9, 2007 2:10 pm (PST)
Hello Dan,
I won't take the bait right now since I have to prep
for a BSA father- son(s) camping trip this weekend. Mind if I take a rain
check for next week? My two young sons (14 and 7) need me far more than me
taking the time in writing a thought-provoking, insightful and witty
response to your comments (I flatter myself, I know). Just pray that I
don't freeze to death tonight camping in the mountains of North Carolina
otherwise the world will be a worse place for not hearing my rebuttal to
some of your silliness (I'm not saying "silliness" is a bad
thing, by the way).
I just didn't want my silence for a few days to be
interpreted as any kind of tacet agreement of your points and an
"admission" that I had any kind of agenda in mind when I wrote my
editorial comments about the possible inclusion of more advanced profile
editing/creation tools in Adobe products.
I've already taken too much of my time writing this
note stating that I don't have the time right now to properly
"rebutt" you.
Get back to you soon!
:-)
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
.
Re: Printer profile bad?
Posted by: "Richard Wagner"
Sat Nov 10, 2007 12:41 pm (PST)
On Nov 9, 2007, at 8:41 AM, DMargulis wrote:
Certainly as a color management consultant it seems
undesirable for
the general public to be able to edit existing profiles
without the
aid of a color management consultant.
No, when looking at the effect of the general public
having the power, but not the knowledge to properly "edit"
profiles, it becomes very UNdesirable to add this functionality to
Photoshop. We are finally getting to the point where there are good
profiles available for common inkjet printers and papers, and good quality
monitor calibration hardware, software, and profiles, and high-quality,
standardized profiles (and data) for offset printing. Having people hack
these profiles would not be good for color communication. And very few
"color management consultants" routinely "edit"
profiles. Rather, they GENERATE or BUILD new profiles using appropriate
software packages. Ideally, this is done from ACCURATE colorimetric
measurements of target data. This requires having the printed target to
measure and an accurate spectrophotometer, as well as the software. So
should Adobe bundle an Eye-One with proposed profile editing capability in
Photoshop CS4, too?
Wait a minute. This particular PBP was generated
without Adobe's
assistance, no? It was causing a major problem in a
paying job,
right? It was editable in three minutes, right?
No, the "poorly built profile" wasn't
"editable in 3 minutes." As was clearly pointed out more than
once, the "bad" profile was not edited at all. Rather, the bad
profile was used to regenerate approximated measurement data, and that data
was supplied to an expensive profile generation software package to build,
de novo, a new profile. It would have been preferable to use the original
measurement data to re-build the profile, but that was not available. The
old profile was NOT edited in any way whatsoever, and profile editing
software was never used. Both Terry (a color management consultant) and
Peter (a very sharp photographer) used essentially the same tools and
techniques to solve the problem. The tools are standard parts of their
toolbox. ProfileMaker can be purchased for a fraction of the cost of a pro
digital camera body or digital back, or many prime lenses. If you need the
tool, you purchase it. Don't complain because Adobe won't bundle the same
functionality that costs 3+ times the cost of Photoshop for free. There's a
lot in a profiling package (http://www.xrite.com/ product_overview.aspx?ID=
794), and the least important part is "profile editing." Many
people on this List have found this software to be a useful expenditure and
an essential tool. If you feel that editing or creating profiles is
essential, don't wait for Adobe. Just take out your credit card and buy
ProfileMaker or PROFILER. And don't forget to pick up a spectrophotometer.
The new SWOP profiles that you were recently
recommending replaced
PBPs with certain well-documented
peculiarities/defects, right?
No, Terry stated that the SWOPv2 profiles (included
with the Adobe CS3 suite) are not the current SWOP profiles:
Given the prevalence of PBPs, and their ability to mess
up paid
work, and the ease of repairing them in three minutes
or so, is it
all that unreasonable to want to do it without spending
$2,500 or
hiring an electrician (er, color management
consultant)?
Most of the "poorly built profiles" are
output device profiles, and thanks to the fact that most people can't hack
profiles, they're going away on their own. Paper and inkjet printer
manufacturers are supplying better quality profiles, and the old ones get
dropped. More printers are turning to Gracol/SWOP color management, and
those standards are improving and converging. Output profiles in general
should not be used as editing spaces, so there is very little need to edit
profiles - it's better to just build good ones from good measurement data.
As for that "3 minute repair?" It was done
using the $2500 software package.
Similarly, if a person is sophisticated enough to
believe that a
certain PBP has a problem that he feels competent to
attempt to
fix, it is highly unlikely that the resulting new
profile will be
worse than the original.
Wrong. Editing profiles is a minefield. It is very easy
to jack up a profile without realizing it, which is why it is usually
better to build a new profile rather than editing a bad one.
The purpose of profiles (and profile editing) is not to
edit the color of images. There is a reason they are called DEVICE
profiles, because they are supposed to describe the behavior of the DEVICE
- in this case, a combination of paper/inkjet printer or press. Having 16
million profiles, many with the same names, each unique to a specific
image, is not the solution.
Because if the person making it doesn't think it's
better
afterward, he will conclude that he has wasted his time
and goes
back to using the original PBP. And if he *does* think
it's better,
it really doesn't matter what a color management
consultant thinks.
Sounds like you have something against color management
consultants. Note that they are not image editing consultants. If they get
the process fixed and stabilized, everything flows, and they move on to the
next job. That's why they're consultants, and not shop employees. ;-)
If you feel the need to edit profiles, then buy the
software and use it to your heart's content. Currently, there's
ProfileMaker and there's Photoshop, but there's no ProfileShop. But come to
think of it, have you EVER printed a target and built a profile from
scratch? If so, using what software? Which spectrophotometer? RGB or CMYK?
Were the results satisfactory? Did you have to edit the profile afterwards?
If so, how was the experience, and what software did you use?
I certainly agree that progress in the field has been
glacial, just
as I predicted it would be in 1998,
Actually, things are moving rather quickly these days.
Mark Segal posted a rather lengthy discussion of how high quality offset
print publication is being done by those with little prepress experience,
with soft proofing and inkjet proofing, thanks to ICC color management.
More and more print shops "get" color management, thanks to the
efforts of PIA/GATF, GRACoL, SWOP, and the IdeaAlliance. Remote proofing is
a reality. Digital photography has swept through both the consumer and the
pro photography markets, and most pro photographers know color management -
because they have to. Most want to know more, as they have a vested
interest in seeing their work turn out well on press or prints. (For
example, if you want to hang an inkjet print in an auto showroom, and
you've measured the fluorescent lights and found them to be close to 4230K
(CWF F2), build a custom profile designed for that viewing light source in
ProfileMaker and eliminate the metamerism failure that would otherwise
occur with a standard profile built for D50 viewing conditions.) The tools
are available for those who need them, whether for CMYK printing or for
high-quality inkjet printing.
Film is out, digital is in, RAW is the preferred
capture format, and ACR, Lightroom, and Capture One dominate photographers'
workflows. In fact, it's hard to find a photography magazine that doesn't
have multiple articles on color management or digital workflow. Part of
your predictions?
unless it became possible for CMYK professionals to
alter canned
profiles for things like black generation, dot gain,
total ink, and
minor color changes, without spending $2,500 or hiring
a color
management consultant.
If color management consultants consider this an
essential software tool, why shouldn't "CMYK professionals" also
consider it essential? Photographers spend $60k+ on equipment, and many
already own this expensive software - why shouldn't "CMYK
professionals" spend $2,500 on an essential software tool? Many do. As
color management continues to improve, sometime soon there won't be a need
for "CMYK professionals" or color management consultants. Just
like strippers, linotype and monotype operators, photo compositors, and the
like. I'll bet it won't take 10 years.
Because color management consultants have been, shall
we say, slow
to grasp that they probably benefit more from the wide
availability
of profile editing than any other group, they have been
reluctant
to raise their voices to demand that Adobe make the
trivial
programming effort needed to include a rudimentary CMYK
profile
editor in Photoshop. If that reluctance continues, it
can
confidently be predicted that progress will
continue--and that by,
say, 2050, we'll be where we should have been in 2007.
If Adobe were foolish enough to add profile editing to
Photoshop, there would be a huge increase in the the number of color
management consultants needed to straighten out the mess and get print jobs
through the shop. There would also be a huge number of color management
consultants and print shop employees seeking psychiatric care for HPSD -
Hacked Profile Stress Disorder. My prediction is that it won't happen.
--Rich Wagner
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Mike Russell
Sat Nov 10, 2007 3:03 pm (PST)
If Adobe were foolish enough to add profile editing to
Photoshop,
there would be a huge increase in the the number of
color management
consultants needed to straighten out the mess and get
print jobs
through the shop. There would also be a huge number of
color
management consultants and print shop employees seeking
psychiatric
care for HPSD - Hacked Profile Stress Disorder. My
prediction is that
it won't happen.
--Rich Wagner
No. If expensive tools, as such, raised the quality of
work, then the simple act of making text editors more expensive would raise
the quality of written text, and make the job of copy editor easier.
Mike Russell - www.curvemeister.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: J Walton
Sat Nov 10, 2007 7:29 pm (PST)
I don't think anyone is suggesting that Photoshop be
expanded (yet again) to include profile generation or even profile editing
in the way it is being described.
The only reason Custom CMYK is useful, IMO, is in
adjusting black generation. Very few people actually edit the primaries to
make the conversions less crappy, but it's pretty common for someone to
request a different black. In that case you aren't messing with the
measurement data, and you aren't making additional color corrections (what
I think of when I hear profile editing).
If Photoshop could take a profile (with measurement
data included) and allow a custom black and ink density that would be nice.
It would be basically what they already before ICC, and nobody was
complaining that experts were going to have to run around fixing everything
back then.
--
J Walton
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Sat Nov 10, 2007 7:29 pm (PST)
I spoke to soon. For the latest example of the power of
color management with digital photography, Jeff Schewe has just posted a
description of the entire process involved in the printing of his new book,
Real World Camera RAW, including a fascinating visual tour through a modern
pressroom. And the book was printed in Indiana - not Asia!
http:
//photoshopnews.com/feature-stories/printing-rwcr-cs3/
--Rich Wagner
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Sun Nov 11, 2007 9:08 am (PST)
Dan Margulis wrote:
Just to reemphasize Stephen's point, there are three
important
lessons to be drawn from this instructive thread.
1) When you ask a profile to convert something that's
as wildly out of
printer gamut as this particular red is, you're playing
Russian
roulette.
Agreed Dan. What I found interesting from comparing
this profile to the results of using 'similar' conditions was that Steve's
profile only had issues with OoG colours, it behaved as expected for in
gamut colour. I don't have a whole lot of experience with profiles provided
from printers, so my expectation would have been either for a profile that
performed well in all cases or one that was under par in all cases - but
instead it was a mixed bag.
What was also unusual was that the perceptual intent
provided more saturated reds than the RelCol+BPC conversion. where as
experience with other profiles and theory lead me to expect less saturation
in the perceptual transform.
As I don't have profile software and only have
Photoshop, my work around would have been to convert to a well behaved CMYK
first, then from CMYK to the printer's CMYK, if I was forced to use this
profile.
In evaluating a profile's performance, then, colors
like these are
best ignored, because there isn't any right answer.
Concentrate on
ones that the printer has some remote possibility of
hitting.
The profile performs below expectation on OoG colours,
such as intense RGB reds* (greens are also a problem for this profile. An
in gamut red or other hue converted with little change of colour from the
RGB original, as happens with more 'well behaved' profiles such as Adobe
SWOP v2.
If one converts to a 'well behaved' CMYK profile first
and then to the target CMYK, the OoG colours no longer suffer as they did
when going direct from RGB to CMYK, without the intermediate trip to CMYK.
*I would have thought that a HK based printer would
have had a profile that had no issues for reds, with it being such a
culturally important hue!
2) I haven't looked at the profile myself, but Terry,
Stephen, and
Peter all seem to find fault with it. If so, it's no
surprise.
Profiles handed out by commercial printers are like
stock market tips
handed out by printers. If you have some evidence that
the printer
knows WTF he's talking about, then his profiles and
stock market tips
are both to be given some respect. But an unknown
printer--I wouldn't
assume that the profile was worth anything. Which is a
a very strong
argument for those who may find themselves at a
printer's mercy to
learn enough about the process so that that lamentable
situation is
avoided in the future.
From my limited experience with such profiles, they are
often made by two different people. One may be made by a colour management
consultant when the digital proofing system is installed, for example.
These profiles are usually built by somebody that has a good handle on the
complexities of profile generation packages and profile creation. These
profiles are usually well behaved, unlike the profile that sparked this
thread. The second set of people generating profiles for/at these print
companies are the printer's staff.
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Andrew Haley"
Sun Nov 11, 2007 9:08 am (PST)
Peter Figen writes:
I just looked at Steve's Midas profile this morning.
Overall, it's
pretty close to SWOPv2 in its basic look. The saturated
red thing
is definitely a problem, so I used ColorLab to build a
data file
(this was an Agfa profile that had no embedded
measurement data)
and then imported the new measurement data into
ProfileMaker and
built a new profile that has much better red rendering.
I sent the
new version directly to Steve. The whole process took
about three
minutes.
OK, so I'm feeling really dumb. How do you use ColorLab
to build a data file from a profile? I've been trying to figure it out all
morning.
Thanks,
Andrew Haley.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Sun Nov 11, 2007 9:08 am (PST)
On Nov 10, 2007, at 4:59 PM, J Walton wrote:
I don't think anyone is suggesting that Photoshop be
expanded (yet
again) to include profile generation or even profile
editing in the
way it is being described.
I hear what you're saying, but that's not what I read
in Dan's post or other posts. The "fix" for the bad profile that
started this thread was not simply black generation, but a color problem.
The minimal editing tools that you suggest would not have solved the
problem with the bad profile. That profile really needed to be rebuilt with
a quality profile generation app like ProfileMaker or Profiler. Dan claimed
it could be "edited in 3 minutes" and that that functionality
should be included in Photoshop. No way.
--Rich Wagner
___________________________________________________________________________
Press profiles, use of
Posted by: palmiter_gene
Mon Nov 12, 2007 3:20 pm (PST)
I wrote to the printer we us and asked for press
profiles and suggested working spaces. I want to get more consistant
results. I got this back...
"Attached is our recommended RGB working space
profile (Standard Working Space.ICC) and the corresponding CMYK working
space profile (ISOnewspaper30v4GCR4.icm). Our commercial web printing work
is done only on one press. If you are doing sheetfed work with us please
let me know and I will supply a different CMYK working space
profile."
Can someone suggest how I put these to use?
Thanks
Gene Palmiter
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Stephen Marsh
Mon Nov 12, 2007 3:31 pm (PST)
Gene, for a start, you could read this thread in full,
you will learn
a lot from some of the replies:
http:
//tech.groups.yahoo.com/group/colortheory/message/18749
If you made the two profiles available for inspection,
then interested
list members could comment.
Regards,
Stephen Marsh.
___________________________________________________________________________
Re: Press profiles, use of
Posted by: palmiter_gene
Mon Nov 12, 2007 7:50 pm (PST)
Dozens of messages with lots of information...do you
really think that if I don't know how to put profiles into Photoshop and
InDesign that I will understand what all that information means? I get the
idea of why we want profiles for the press and I asked the printer for
them...how do I use them?
Thanks
Gene Palmiter
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Stephen Marsh
Mon Nov 12, 2007 7:57 pm (PST)
"Putting them to use" can be taken many ways
Gene.
You must install ICC file in the OS, Adobe apps
reference the OS to find the profiles. You did not mention if you are Win
OS or Mac OS based. Put the profiles where you find the other icc/icm files
on your OS.
Regards,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Tue Nov 13, 2007 12:04 am (PST)
All-righty then, let's take it from the top....
On Nov 9, 2007, at 10:41 AM, Dan Margulis wrote:
Certainly as a color management consultant it seems
undesirable for
the general public to be able to edit existing profiles
without the
aid of a color management consultant. Similarly,
portrait
photographers used to believe that eliminating
negatives was a bad
idea because it seemed to them undesirable for the
general public to
be able to reprint existing work without the aid of a
photographer.
Prepress houses thought that Macintoshes were a bad
idea because it
seemed to them undesirable for the general public to be
able to
modify their own projects without the aid of a prepress
house.
Actually, no, that's not the way I think. My whole
career has been with the attitude of working myself OUT of a job so I can
move on to the next thing that challenges me as opposed to
"protecting" any competitive advantage I may have under the guise
of "job security". I've been quite successful staying employed as
a color management consultant largely due to the incompetence of others in
this field. I suppose if I wanted more "job security" I'd be
promoting the idea of profile creating/editing in Adobe apps and the
subsequent wide dissemination of "color management" to the masses
so I'd have a few more messes to clean up as a result. That would probably
assure me of at least a few more years doing the consulting gig as opposed
to prematurely ending it.
Wait a minute. This particular PBP was generated
without Adobe's
assistance, no?
Actually, I wouldn't necessarily call the profile in
question a "poorly built profile". It was, perhaps, built using a
less-than- robust profile creation application but there's no indication
that the colorimetric data that the profile application used was anything
but "correct". There's a big distinction between the measurement
data used as the "raw" material from which a profile is created
and the profile creation software itself. Either one can result in a
"poorly built profile".
It was causing a major problem in a paying job, right?
You know, we actually don't know if it would've caused
a problem or not. All we know is the we didn't prefer it's handling of
out-of-gamut colors, that's all.
It was editable in three minutes, right?
Absolutely not. First off, I didn't EDIT the profile at
all, I built an entirely NEW profile by extracting the colorimetric data
from the original profile and simply using a different profiling
application to build the new profile. The issue with the original profile
was, apparently, the gamut mapping calculations in the profile creation
application itself. As far as I know, there's no way through simple profile
editing to change the gamut mapping inherent in a particular profile.
By the same token, if Adobe had the ability to create a
profile and the result was something with very convoluted gamut mapping, no
amount of editing this profile in an Adobe app or any other profile editing
application would fix this issue.
The new SWOP profiles that you were recently
recommending replaced
PBPs with certain well-documented
peculiarities/defects, right?
I'm not sure I know what you're talking about.
I think you're implying that the new "G7"
family of profiles, specifically "SWOP2006_Coated3.icc" and
"SWOP2006_Coated5.icc", were meant to replace the Adobe-created
"USWeb(Coated)SWOPv2.icc" due to some deficiency in the Adobe
profile. That would not be the case at all. These new SWOP profiles
represent the latest thinking (the "G7 Methodology") in press
calibration and process control techniques as well as a move to a
"shared visual appearance" approach to press calibration metrics.
Within months we should see these current SWOP profiles getting the
official "TR" designation of TR-003 and TR-005.
Outside of this list, you never hear of these supposed
"certain well-documented peculiarities/defects" of the Photoshop
SWOPv2 profile.
Given the prevalence of PBPs, and their ability to mess
up paid
work, and the ease of repairing them in three minutes
or so, is it
all that unreasonable to want to do it without spending
$2,500 or
hiring an electrician (er, color management
consultant)?
Your premise is wrong. A gamut mapping issue such as we
saw in the "Midas" profile built using Agfa ColorTune can not be
un-done by a profile editor.
To be sure, many people correct badly using curves. No
matter how
incompetent the execution, however, they almost always
make the
picture look better. Because even the incompetent know
to do a
Command-Z after they apply curves, and if they don't
think they made
the picture better, they conclude that they've wasted
their time and
they stick with the original. And if they *do* think
they've made
the picture better, it really doesn't matter what a
professional
retoucher thinks.
If they think an incorrect curve move has made the
picture better, so be it. That's an "artistic" opinion, nothing
more.
A profile is NOT part of the creative or artistic
process of creating an image in my opinion. An output profile is about 1)
the "character" (characterization data) and behavior of the
output device and 2) the separation parameters, if its CMYK, that will
result in the optimum printing conditions for that device (total ink, gray
balance stability, etc.). Granted, certain types of images may benefit from
a certain style of black generation, but a profile should not be
"tailored" for a SPECIFIC image in the same way editing a curve
applies to a specific image.
Similarly, if a person is sophisticated enough to
believe that a
certain PBP has a problem that he feels competent to
attempt to fix,
it is highly unlikely that the resulting new profile
will be worse
than the original. Because if the person making it
doesn't think
it's better afterward, he will conclude that he has
wasted his time
and goes back to using the original PBP. And if he
*does* think it's
better, it really doesn't matter what a color
management consultant
thinks.
Frankly, I don't think a person who has built a new
profile can have an opinion about whether the profile is better OR worse as
a result of their "edit" unless they have intimate knowledge of
the output device for which the profile was intended. If it's a profile for
their inkjet printer, they may, but if it's a profile that will ultimately
be used to create a separation for an offset printing press, they're not in
a position to know one way or another whether the profile is better or
worse that what they started with.
I certainly agree that progress in the field has been
glacial, just
as I predicted it would be in 1998, unless it became
possible for
CMYK professionals to alter canned profiles for things
like black
generation, dot gain, total ink, and minor color
changes, without
spending $2,500 or hiring a color management
consultant. So, yes.
There has been significant progress over the last ten
years--
probably so much so that we have now reached the point
we would have
been at in Y2K had rudimentary profile editing been a
part of
Photoshop from 1998 onward.
I'm not comfortable with folks that make predications
on the future. Seems they have a vested interest that the outcome is
favorable, at least from their perspective.
Because color management consultants have been, shall
we say, slow
to grasp that they probably benefit more from the wide
availability
of profile editing than any other group, they have been
reluctant to
raise their voices to demand that Adobe make the
trivial programming
effort needed to include a rudimentary CMYK profile
editor in
Photoshop. If that reluctance continues, it can
confidently be
predicted that progress will continue--and that by,
say, 2050, we'll
be where we should have been in 2007.
Well, one only has to take a look at the
"progress" that the Classic CMYK engine has made in the past,
what, 25+ years to know that it may not be in our best interest to risk
Adobe monopolizing the profile creation/editing by including this as part
of Photoshop or Creative Suite. As a color management consultant, I DO have
a vested interest in keeping some of the best color minds at X-Rite and
other companies employed so as not to see development of these applications
stagnate (some would argue, successfully I think, that that has already
happened with the X-Rite/Gretagmacbeth merger). If Adobe wants to create a
separate product/application that competes on the same playing field as
X-Rite PROFILER and ProfileMaker, perhaps we WOULD all be better for it but
if they included it as part of Photoshop either for free or a small premium
over the "normal" Photoshop and it results in the demise of the
current state-of-the-art in profile creation/editing applications, I think
we'd all be the worse for it.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Stephen Marsh
Tue Nov 13, 2007 5:57 am (PST)
I now have more time for a better reply Gene.
You *install* the profiles, most commonly by placing
them into a designated directory in the operating system where .ICC/ICM
profiles reside*. The folder path is different between Mac OS and MS Win
OS, and can vary between different versions of the OS. Such folders can be
found by doing a search for .icc or .icm and opening the containing folder.
Some folder view settings may restrict view of these folder locations in MS
Win OS. A simpler method under MS Win OS is to simply right click on the
profile and choose the "install profile" option. (*Adobe may
store and reference some key profiles in a separate directory to the OS and
may reference both locations, where as other apps may only use the OS). One
can also use the MS Color control panel applet on XP (unsupported powertoy)
to install profiles and also to view/compare 3D gamut plots.
Once the profiles are installed on your unknown OS (and
perhaps after restarting Photoshop), it is your choice whether you change
your colour settings preferences to use these RGB and CMYK working spaces.
I personally would not do so, and simply use these profiles (converting) on
a document by document basis for this printer/project and leave my regular
colour prefs alone. Each to their own.
The press profile may or may not be good, which is
where the previous thread offered good advice for evaluating press profiles
and their results in Photoshop. Be that as it may, the supply of the press
profile is understood. Where I would have more interest, questions and
possible concern is in using this printer's unknown custom RGB working
space over what the image at hand may be residing in (a well known,
suitable space). Will detail be clipped in a relcol transform between RGB
working space profiles, that would otherwise be retained in a perceptual
conversion to CMYK if the image was kept in the original RGB?
Installing the profiles may be the least of your issues
Gene!
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Les De Moss"
Tue Nov 13, 2007 5:12 pm (PST)
Stephen-
Why would a printer supply a custom RGB working space,
rather than just a CMYK profile for their press, into which a well-known
and suitable RGB file would be converted? What is the reasoning behind
this?
Les De Moss
DigiGraphics LLC
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Tue Nov 13, 2007 10:07 am (PST)
My mistake on the math. Should've said "15+
years" in the paragraph below. After reading my post, I found it
interesting that Photoshop pre-dated the invention of the Apple Macintosh
by 2-3 years!
Terry
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Dan Margulis
Tue Nov 13, 2007 5:12 pm (PST)
J Walton writes,
I don't think anyone is suggesting that Photoshop be
expanded (yet
again) to include profile generation or even profile
editing in the
way it is being described.
No. I would suggest ignoring representations to the
contrary. However, it is certainly reasonable to suggest being able to
import third-party profiles and manipulate them to an extent competitive
with 1992 Custom CMYK.
The only reason Custom CMYK is useful, IMO, is in
adjusting black
generation. Very few people actually edit the primaries
to make the
conversions less crappy, but it's pretty common for
someone to request
a different black.
Certainly black generation (together with manipulating
total ink limit) are the *main* reasons that people stick with Custom CMYK.
However, anyone who works with a variety of unknown (or unreliable)
printers needs to be able to manipulate dot gain as well. It's common to
have to send work on a continuing basis to printers with little information
about their capabilities or how consistent their work is. In that case,
there's little alternative but to continually update the profile for dot
gain as more information becomes available.
The clearest indication that a *lot* of people do more
than generate black was in 1998. Custom CMYK has always had
channel-by-channel dot gain control, even though the default is an
all-channel setting. With Photoshop 5 in 1998, Adobe upgraded it so that
instead of a simple midtone control in each channel, we can write full
curves to alter the dot gain setting in any tonal range. That's pretty
sophisticated stuff--anybody for whom a midtone tweak to an individual
channel isn't sufficient is somebody who knows what they're doing.
I rated this addition as one of the 10 most important
new features of Photoshop 5, but I wasn't the one who suggested it--I was
most pleasantly surprised when it appeared. So Adobe must have had
information from somewhere that many users wanted the feature.
Similarly, (although I didn't rate this as a
particularly important feature) Adobe added the capability within the Ink
Colors dialog of Custom CMYK to specify ink colors in LAB as well as the
traditional xyY. They would scarely have added that if they didn't think
that a significant number of people were editing ink colors.
If Photoshop could take a profile (with measurement
data included) and
allow a custom black and ink density that would be
nice.
It would, but it would hardly be a credit to the
program only to be able to do things half as well as in 1992. Extracting
the information and regenerating a simplified profile is easy from the
programming POV--if you have harvested enough to be able to enter a new
black generation and ink limit on the fly, you've got enough to allow dot
gain manipulation and limited color editing as well.
It would be basically what they already before ICC, and
nobody was complaining
that experts were going to have to run around fixing
everything back then.
Right. Part of the reason was good software design. The
controls to alter ink colors and channel-by-channel dot gain were well
disguised and by no means beginner-friendly. Nobody was going to get into
those controls by accident, and anybody brave enough to start throwing new
values into such a dialog almost certainly knows what they're doing.
Dan Margulis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Fred D Yocum"
Tue Nov 13, 2007 3:54 pm (PST)
As one graphic designer to another (I am making an
assumption here), I feel your pain, however -- you do need to read all the
messages and anything you can find on colour management. I recommend
"real world colour management". Profiles are not like fonts that
you drop into a font folder and they work. Either you pay a coolour geek to
manage your system and give you some rudimentary training or you read,
read, read, read. This is an area where a little knowledge is a dangerous
thing...
Dozens of messages with lots of information...do you
really think that if
I don't know how to put profiles into Photoshop and
InDesign that I will
understand what all that information means? I get the
idea of why we want
profiles for the press and I asked the printer for
them...how do I use
them?
------------------
Frederick D Yocum,
Graphic Designer
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Andy Adams
Wed Nov 14, 2007 5:54 am (PST)
Gene,
I can't help but respond to your situation.
Over the years I have been in the same situation, which
has brought me to this conclusion; printers typically haven't gone to the
trouble of profiling their presses under a controlled (aka: industry
standard) enviornment. And if they did, are likely to have moved from that
"controlled printing" by time they print your job. The exception
is a printer who regularly tries to monitor his presses (and their
proofers) so that they all print as close as possible to the standard
profile they sent you.
Bottom line, I view the CMYK profile I recieve as the
printer's goal, and will put it in my "Color Settings" (Working
Spaces > CMYK). That way I will "see" how my files will (in
theory) print. BUT, I will not use them to convert to CMYK. Why? Experience
has affected my faith in supplied profiles. So I stick to one of the 42
photoshop settings (others probably have more) I have created based on the
photos subject, the paper, and the typical dot gain for that type of stock.
After converting I do not embed my profile, because I
want to see how it looks through the supplied profile I have loaded in
"Color Settings". If the customer expects to see their profile
embedded (not typical in my case) then I embed the converted photos with
the supplied profile. Yes, I have just lied to the printer. So what. The
file I have supplied is balanced, color corrected, etc., and will print
just fine. And I did it all with a profile that has served me well. A plus
to this way of doing things (for me) is that I can always recreate any of
the 42 profiles I use by just going back into Photoshop and adjusting the
GCR/dot gain/Ink Colors, instead of relying on a pricey program like
ProfileMaker (which I love by the way).
As for the supplied RGB space. It could be that some
"in-house" guru has tweaked a "standard" color space,
which could lead you to believe they know their stuff - but without being
able to open it (which is always nice to be able to do) you really don't
know if you can trust it. So, I don't use them. Typically, I stick with
Adobe RGB.
The actual hard part in all this is to get your proofer
to mimic the press the job will print on. But since they sent you their
press profile you now have what you need to place in your proofing software
(as the source profile).
I have been profiling presses and proofers for years
and know the difficulty in getting everyone on board when it comes to
keeping presses and proofers running to a developed plant
"standard" (which were I work now is GRACoL 7). It is hard enough
to get people to care when you are in charge and have to authority to make
their life miserable, but when your work is going somewhere else (possible
out of the country) I tend not to trust what I am given. So I do as
described above.
There are some color management consultants on this
list that have made negative comments on prepress folks being able to
actually supply good information to clients sending in CMYK file. As a
prepress person I totally agree. It is just a sad truth. It is not just
prepress people - it is people in general. Even with a better way of doing
things (color managing, color correcting, etc.) most tend to just do what
they feel is good enough. So, stick with this colortheory group and you
will be able to go beyond good enough.
Andy Adams
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "PIA GATF"
Wed Nov 14, 2007 11:41 am (PST)
I agree, with Andy (below) maybe this will help please
share the following
. . . .
Printing to Gray Balance. . . .
Most recently there has been a lot of discussion about
©¯printing to gray balance©˜. The new GRACoL (G7)
describes the methods to achieve gray balance at press.
What©ˆs so important about gray balance at
press? The concept of gray balance is essential for excellent color
reproduction in scanning, proofing, and in the pressroom. In scanning,
images that are not in gray balance are considered
©¯casted.©˜ Images that are casted show a magenta,
cyan, or yellow (or combinations of M-C-Y) color appearance in the
highlights, midtones, and/or shadows. Casted images require color
correction to remove the unwanted colors. Images that are in gray balance
only need to be adjusted for specific areas of color enhancement, i.e.
greener grass, or bluer skies.
Proofing systems must be able to reproduce neutral gray
without any cast as well. If the file is correct and the proofer introduces
a cast, then all the color is shifted away from gray balance. A proof that
is casted will require the press to print away from neutral gray to match
the proof. The little ©¯secret©˜ of process color
printing at press is that you can only print two ways on press - in gray
balance or casted - that©ˆs it! You are either neutral throughout
the tone scale, or you are casted in some way. If you©ˆre casted,
color reproduction suffers. The fact is that all press operators abide by
this principal. Press operators look at a printed press sheet and notice
casts of too much magenta, cyan, or yellow and reduce whichever color is
creating the cast. The control for the press operator is more or less ink,
however the TVI, or dot area, is equally important. The press operator
can©ˆt change the size of the dots on the plate, but he or she
can change the gain by adding or subtracting ink.
The major problem in printing today is that the values
on the plate are incorrect. The values on the plate need to be adjusted for
all four colors, each color Y-M-C-K, needs its own plate curve to reproduce
neutral gray at press. A lot of printers have only one plate curve for all
colors! The other issue is weight - how dark or light is your midtone
reproduction? Screen builds and Photoshop images are adjusted for around a
20% TVI ,or midtone gain, meaning a 50% patch will print as a 70% value.
Most linear plates (50% = 50%), gain around 14 to16% on press, and print
too light for separations created in Photoshop.
The majority of printing plants I encounter have this
platemaking problem. It is impossible for the pressroom to control gray
balance and color with the wrong size dots on the plates. The procedure is
to print a test form with complete tone scales at the required density.
Next, compare the scales against a standard and adjust the plate values
accordingly. Every color bar should include a three-color gray patch
represented by 50C-40M-40Y. This patch, when printed at the correct density
and dot gain, will appear neutral - without any casts. It can also be
measured with a reflection densitometer. The densitometer needs to be set
for ©¯ALL©˜ filter readings, now the yellow, magenta,
and cyan inks can be measured as a density. When all three filter readings
are equal, the patch is neutral. A 0.03 density among all three filter
readings is the tolerance for an acceptable neutral appearance.
If you have any questions, or would like me to help you
on-site, please call me here at PIA/GATF. I©ˆll include my
personal cell phone number as well.
Dan Remaley PIA/GATF
Senior Technical Consultant Process Controls
412.259.1814 Office
412.889.7643 Cell
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "icccolor"
Thu Nov 15, 2007 8:32 am (PST)
Hi Dan,
I agree with you about "all filter" reading
mode to find out if the gray balance IS OK.
This is the way we measure and calculate gray balance
curves with our software (PerfX Press Curves™).
We have great success with this approach, for many
printing processes like offset, gravure, flexo, newsprint, etc.
It is easier for the pressman to read "equal
densities" to check gray balance, compared to Lab.
regards,
Louis Dery
Color Management Expert
www.tglc.com
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Thu Nov 15, 2007 4:28 pm (PST)
As far as I know "all" CTP-plates are made
(almost) linear these days. Using compensation curves in order to
compensate for "balance errors" in a time of
"calibration" and "profiles" is a strange move...
Profiles should emulate printing curves (TVI), ink trapping, gray balance
etc.
Will there be printers with and without "gray
balance-adjusted plates" in the near future? For different screen
rulings, different screening technologies, different ink batches?
Was the past without gray balance? I have no clue.
Paul Foerts
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Thu Nov 15, 2007 4:28 pm (PST)
Andy Adams wrote on Wed Nov 14, 2007 5:54 am ((PST)):
Over the years I have been in the same situation,
which has brought me to this conclusion; printers
typically haven't gone to the trouble of profiling
their presses under a controlled (aka: industry
standard) enviornment. And if they did, are likely to
have moved from that "controlled printing" by
time
they print your job. The exception is a printer who
regularly tries to monitor his presses (and their
proofers) so that they all print as close as possible
to the standard profile they sent you.
It is up to the printer to match a "contract
proof". If there is no hard copy reference and not enough expertise,
discussions easily end in dire straits.
I do not know such a thing as a "standard
profile". I suppose you refer to a standard printing condition. The
contract proof should match this condition.
I have been profiling presses and proofers for years
and know the difficulty in getting everyone on board
when it comes to keeping presses and proofers running
to a developed plant "standard" (which were I
work now
is GRACoL 7). It is hard enough to get people to care
when you are in charge and have to authority to make
their life miserable, but when your work is going
somewhere else (possible out of the country) I tend
not to trust what I am given. So I do as described
above.
As far as I know presses cannot be profiled as they
cannot be calibrated... You can make profiles using printed targets.
If you have 16 targets on one sheet, they will all be
different. If you have pulled several sheets from the test run they will
all show differences (minor or big). You will find that the press operator
is always busy with the ink keys. You see the color variation of the output
and will agree: an offset printing press is a profile editor! My suggestion:
(for routine jobs) always refer customers to canned profiles which are
freely available for standard printing conditions. (a plant standard is
nice but comes at a cost)
Let the press operator do the tweaking with his profile
editor...
Paul Foerts
___________________________________________________________________________
Press profiles, use of
Posted by: Andy Adams
Fri Nov 16, 2007 6:47 am (PST)
Paul Wrote:
As far as I know presses cannot be profiled as they
cannot be
calibrated.. . You can make profiles using printed
targets.
If you have 16 targets on one sheet, they will all be
different. If you have pulled several sheets from the
test run they will all show differences (minor or
big). You will find that the press operator is always
busy with the ink keys. You see the color variation of
the output and will agree: an offset printing press is
a profile editor!
My suggestion: (for routine jobs) always refer
customers to canned profiles which are freely
available for standard printing conditions.
(a plant standard is nice but comes at a cost)
Let the press operator do the tweaking with his
profile editor...
All your points have merit. And since this group is
about color correction and not so much color management I will just comment
this one last time on this subject.
A press can be profiled. Problem is, that profile
reflects that one moment in time. And that profile may be no more than an
officially worthless profile, since the pressman may not have taken the
occasion seriously. So using the press profile as your "standard"
for your proofs to reach hasn't been too successful.
So far the best approach I have found is 1st, to try
and adopt an industry wide accepted "standard" (in our case we
try to match GRACoL 7), then 2nd, control your presses (by way of curves
for each press - since each prints differently) and proofers to match it.
Easy? No. Possible? Yes. So our proofer is the "stake in the
ground" and our presses try to match it. Regularly monitoring the
presses and proofers is key to success.
I am starting to yawn, I guess this subject can be
boring.
Andy Adams
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Lee Clawson
Fri Nov 16, 2007 8:05 am (PST)
on 11/15/07 7:47 PM, Paul Foerts at
paul.foerts@scarlet.be wrote:
As far as I know presses cannot be profiled as they
cannot be
calibrated... You can make profiles using printed
targets.
Paul,
This is first time I heard that a press can't be
calibrated. Could you explain why this is so.
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Sat Nov 17, 2007 4:06 pm (PST)
Lee,
Calibration = adjusting to a specification or a
standard within tolerance or adjusting to "nominal".
What can be calibrated on a press?
The ink keys settings?
The press or ink temperature?
Etc...
Is matching a standardized printing condition (SWOP
etc.) calibration?
When you stop the press, your "calibration"
is gone.
When you change plates, your "calibration" is
gone.
When you choose different paper, inks...
I suppose you are thinking of process control when
using the terminology "calibration".
If you would try to print one big "patch" of
CMY-gray - covering the entire sheet - and you would cut this sheet in
pieces, you would have a nice collection of different grays. With the help
of a little "doubling" things could get even more convincing...
I'm pretty sure that it does not make any difference if
you print this big "patch" on a so called "calibrated"
press or on a "normal" press.
Please note:
Process control is the key to quality. Standards should
be "references" with practical tolerances. Contract proofs are
preferable targets, can stimulate standards and protect the innocent in
case of "misunderstandings" Better 1 (canned) profile of an
accepted standard printing condition than 1000 (customized)
"press" - profiles (sic)
Give the printer a target and he will match it (within
limits) with his profile editor, the printing press. :-)
Could we agree?
Paul Foerts
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Tue Nov 20, 2007 8:56 am (PST)
Lee,
The only thing i'm trying to tell is that there is no
need to call every setting or adjusting "calibrating" when we are
talking about color management.
About working with a printer and be satisfied: Choose
your printer before preparing the job. Use the printer's guidelines for job
preparation. Send some test spreads (files) to the printer for evaluation.
Let him provide a contract proof. If you are satisfied with the results, go
for it!
Paul Foerts
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Henry"
Tue Nov 20, 2007 6:39 pm (PST)
On Nov 19, 2007, at 6:22 PM, Paul Foerts wrote:
The terminology "calibration" has alway been
used in the domain of
measuring equipment. In recent? history the terminology
was used for
scanners, monitors, printers and later camera's. To be
"calibratable", these
devices needed to be "stable" by definition.
Moving targets cannot be "calibrated"
This terminology battle :-)) is important. It helps
people to learn about what is possible and what is not.
The observation above cannot be repeated often enough.
I believe that the point Paul is making is unpopular with the
"calibrationist" crowd, and I'll add that the misinformation that
has been perpetuated has proved to be difficult to correct. It is assumed
by other parties that may be less informed that the
"calibrationist" is experienced and capable and thus has a very
good understanding of presses and the variables of printing. There are
probably some reading this thread that are of the belief that a press can
be calibrated - mainly because this is what they would like to hear, and
also because they are being told that this is the case by folks who are
tops in the color management field.
Let me repeat again that I am not
"anti-profile" or "anti-color management". On the other
hand, I will also repeat that profiles and color management are not the
"magic" that they have been claimed to be. There isn't a creative
or layout designer in the world that wouldn't like to hear that color
accuracy is no longer a guessing game, that these problems have all been
solved. If only the proponents had been as forthcoming with all of the
things that profiling and color management could not solve, or weren't
designed to solve, we would now have a much smaller tiger by the tail. I
agree with Paul that the word "calibration" does not apply to a
printing press. This word is overloaded with meanings that do not apply to
a press - but it does tickle the ear of those who don't want to be confused
by the facts.
If you would try to print one big "patch" of
CMY-gray - covering
the entire sheet - and you would cut this sheet in
pieces, you would have a
nice collection of different grays.If you would try to
print one
big "patch" of CMY-gray - covering the entire
sheet - and you would cut this sheet in pieces, you
would have a
nice collection of different grays.
If an operator were to have infinite resources of ink,
make-ready and time, a perfect sheet may occur. If, however, any job
printing is to take place, compromises must be made - must. Otherwise, we
will all be sitting around waiting for perfect press conditions. All the
while, the opposite is the apparent claim: no compromises and accurate
color. Oh, but when pinned down, even the "calibrationist" will
back-peddle and say that there is no such thing as a perfect color match,
and may even admit that there are other unfulfilled promises. But this
admission is only offered when it is forced - and this is misleading.
This doesn't mean that a "general" profile
isn't possible. A profile is a description of a press in a certain state.
But, the fact remains that a press and the printing that comes out of it is
almost necessarily variable. A printing press is not a
"calibratable" machine. It isn't stable enough for a snapshot to
offer a precise portrayal, and a profile would more reasonably be offered
as something that can be used as a general guide. For argument: If a
digital camera can't be precisely calibrated for outdoor use, how can a
printing press?
The work done by color management scientists can be
useful. But color management has also been misleading, and its claims often
lead to misunderstandings. How many times have we been cautioned that
"education" is the key. That designers must be educated, yet,
what a designer hears is that color management has carried all of their
worries away. After hearing this, how much education do you think that a
designer will feel the need for?
It has even gotten to the point now that more
"boutique RGBs" are popping up. I don't mean JoeRGB or Bruce RGB,
but "ABC Printing Co RGB" and "XYZ Printing Co RGB",
along with the "XYZ Photo Agency RGB", are beginning to muddy up
the waters even more. Isn't the presumption here that a "Custom"
RGB offered by a printer or agency is a "better" editing space or
a "more calibrated" solution? I wonder how many list members
consider that the situation prompting the original post was a fluke, or one
that happens more often?
Henry Davis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Dan Margulis
Wed Nov 21, 2007 5:59 am (PST)
Terry writes,
You know, we actually don't know if it would've caused
a problem or
not. All we know is the we didn't prefer it's handling
of out-of-gamut
colors, that's all.
Fair summary. I apologize for overstating the case in
that particular sentence.
Absolutely not. First off, I didn't EDIT the profile at
all, I built
an entirely NEW profile by extracting the colorimetric
data from the
original profile and simply using a different profiling
application to
build the new profile.
Yes. You have already explained how you edited the
profile. I don't think that anyone misunderstood your procedure. It has
become an unfortunate characteristic of this list that when people are
losing an argument they throw up a smoke bomb by suddenly redefining
commonly-understood phrases and declaring that their opponent is misusing a
term. You can certainly call your process whatever you like, but I call it
"editing". If you have a problem with my use of the verb "to
edit", that's fine, but it's not a topic of interest.
I think you're implying that the new "G7"
family of profiles,
specifically "SWOP2006_Coated3.icc" and
"SWOP2006_Coated5.icc", were
meant to replace the Adobe-created
"USWeb(Coated)SWOPv2.icc" due to
some deficiency in the Adobe profile. That would not be
the case at
all.
I was not implying this about the new SWOP profiles,
although they do move away from the blue problem in SWOP v2. I *was*
implying it about the GRACOL2006_Coated1v2.icc as a replacement for the
Adobe-created US Sheetfed Coated v2.
Outside of this list, you never hear of these supposed
"certain well-
documented peculiarities/defects" of the Photoshop
SWOPv2 profile.
How many lists have a lot of people who know color
correction and offset presses? But setting that aside, the blue problem of
the SWOP v2 profile is amply documented with example images in both Canyon
Conundrum and PP5E, which compares its performance in several images with
four other "SWOP" profiles.
Your premise is wrong. A gamut mapping issue such as we
saw in the
"Midas" profile built using Agfa ColorTune
can not be un-done by a
profile editor.
The simplified profile editor that I have suggested for
Photoshop would do it automatically.
A profile is NOT part of the creative or artistic
process of creating
an image in my opinion. An output profile is about 1)
the
"character" (characterization data) and
behavior of the output device
and 2) the separation parameters, if its CMYK, that
will result in the
optimum printing conditions for that device (total ink,
gray balance
stability, etc.).
Not in my view. A profile is a means to an end, nothing
more or less. To the extent that it assists in achieving a quality result
it is good, and to the extent it gets in the way, it's not. To be
successful, the profile needs to account not just for the behavior of the
output device but for that of the humans who run it. A profile based on the
average measured performance of the press under optimal conditions may be
successful if the job is printed by the company's most disciplined shift
and inadequate otherwise. If the printing is expected to be careless, a
defensive profile is in order.
Granted, certain types of images may benefit from a
certain style of black generation, but a profile should
not be
"tailored" for a SPECIFIC image in the same
way editing a curve
applies to a specific image.
I'm not sure that I understand this statement. If
you're acknowledging that an unusual black generation can pay big dividends
in certain images, you're right, but if you want to do that without taking
a lot of extra time and spending a lot of money, you'll need to upgrade to
Custom CMYK.
Tailoring a profile to a specific image isn't
philosophically repugnant, but we have to ask whether it makes any sense.
Generating an alternate black without editing the profile is doable but it
isn't easy. Removing a cast during conversion by editing the profile is
also doable but it takes twenty times as long as doing it in Photoshop. So,
I agree that it doesn't make a lot of sense to edit image-by-image except
for black generation and total ink.
Frankly, I don't think a person who has built a new
profile can have
an opinion about whether the profile is better OR worse
as a result of
their "edit" unless they have intimate
knowledge of the output device
for which the profile was intended.
If you or I build a press profile today, perhaps we
have that intimate knowledge. A week from now, a month from now, we won't
have that knowledge, and it's anybody's guess whether the profile is still
valid.
If it's a profile for their inkjet
printer, they may, but if it's a profile that will
ultimately be used
to create a separation for an offset printing press,
they're not in a
position to know one way or another whether the profile
is better or
worse that what they started with.
This is not real-world. If we send a job to a certain
printer using his supplied profile and every image comes back slightly
darker than expected, we don't have "intimate knowledge" of
exactly why, but we are certainly in a position to make the profile
better--not perfect, but better--in about ten seconds in Custom CMYK for
free. Or, we can hire a color management consultant to make a new profile
that we can't edit if the same situation arises.
Similarly, if we have a profile that has previously
given good results, but we are now going to print with a different stock,
it isn't difficult to know whether dot gain is likely to increase,
decrease, or roughly stay the same. If it's one of the first two options,
we can certainly make a better--not perfect, but better--profile.
These sorts of on-the-fly tweaks are one of the things
that differentiate those who can consistently extract good quality out of
the slimy mire that is today's commercial printing environment. Such people
can get better quality out of a hacked Custom CMYK profile that they can
change over time than with a theoretically better, but uneditable profile.
Consequently, for those skilled persons who have to deal with many
different commercial printers, a system of uneditable profiles is a
nonstarter, period, just as it was a nonstarter in 1998.
Well, one only has to take a look at the
"progress" that the Classic
CMYK engine has made in the past, what, 25+ years to
know that it may
not be in our best interest to risk Adobe monopolizing
the profile
creation/editing by including this as part of Photoshop
or Creative
Suite. As a color management consultant, I DO have a
vested interest
in keeping some of the best color minds at X-Rite and
other companies
employed so as not to see development of these
applications stagnate
(some would argue, successfully I think, that that has
already
happened with the X-Rite/Gretagmacbeth merger).
There's a lot of truth in the above, and it just
recently got even more true: X-Rite has now snarfed down Pantone, so
there's even one less independent player, which is likely to result in more
of the same kind of unfortunate consequences you discuss.
OTOH, you should probably give thought to the meaning
of all this consolidation. The marketplace of people who could conceivably
purchase color management products has increased astronomically in the past
few years. We have been told continuously since 1998 that there is
tremendous momentum toward adoption and that all the pieces are coming
together, and that now it's an assumed part of every professional
operation. We have turned at least 250 corners in that time. There are now
a number of respected color consultants with proven track records,
something that was lacking, say, five years ago. Everything would indicate
that these last few years would be a time of enormous growth for X-Rite and
its former competitors, and that business conditions for them would be even
better than, say, those enjoyed by those who know how to color-correct
images professionally.
Instead, these companies can't even stay in business.
These mergers are not like Adobe-Macromedia, where two giants find a fit.
They're because the companies are failing as standalone entities.
If Adobe wants to
create a separate product/application that competes on
the same
playing field as X-Rite PROFILER and ProfileMaker,
perhaps we WOULD
all be better for it but if they included it as part of
Photoshop
either for free or a small premium over the
"normal" Photoshop and it
results in the demise of the current state-of-the-art
in profile
creation/editing applications, I think we'd all be the
worse for it.
I don't agree that it would hurt the high-end profile
packages to incorporate a capability into Photoshop that could read
incoming profiles and manipulate them to a somewhat larger extent that
Custom CMYK does. Also, as I understand it, X-Rite makes a lot more money
off hardware than its profiling software, and Adobe is not going to compete
with that.
Even if it did retard development of these products,
that disadvantage would be dwarfed by the beneficial effect of having
high-end CMYK users come around to abandoning Custom CMYK and endorsing the
technology that you represent. Easy enough to do, IMHO.
Dan Margulis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Wed Nov 21, 2007 4:10 pm (PST)
Actually, it **is** a topic of interest, because what
you originally called for was for Photoshop to have the capability to
"edit" the profile in the way that Terry did to fix the problem
at hand. Neither Terry nor Peter edited (or made changes to) the original
profile. To "edit" a file means to make changes to that file.
Creating a new profile, de novo, using a profiling application is not
"editing" a profile. The new profile that was created is
structurally different from the original, with completely different
mathematics embedded in it to handle out-of-gamut colors, and double the
number of grid points or vertices of the original. You can NOT create this
new profile by editing the original, nor can you get it by using
"Custom CMYK" or any proposed new version of Custom CMYK. It
would take a complete profile generating application like ProfileMaker or
PROFILER to generate the "fixed" profile, and it would not be
reasonable to bundle something comparable to those large, expensive
applications into Photoshop.
Perhaps you could demonstrate for us how you could edit
the OLD profile using Custom CMYK (or any other tool in Photoshop or
elsewhere) to fix the out-of-gamut perceptual mapping problem that occurred
with that profile, leaving the original number of vertices and other
structural components of the profile intact. Other than the "3 minute
fix" from those with expertise in color management, I haven't seen any
other good solutions to the original problem posted here. Your approach to
editing the profile would be of general interest to the List, since many
here don't own a profiling application.
--Rich Wagner
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Lee Clawson
Wed Nov 21, 2007 5:59 am (PST)
Paul,
Not sure what your work is like but in this studio
there is neither time or budget to send test spreads out for each job. We
asks for proofs and get digital proofs. More often than not the printer
doesn't know what press our job will go on till 24-hrs before the job
starts.
After how specific you talked about calibration vs
process control I had hoped you'd add as much to the way you prepare files
for output. -- Do you receive and use a profile for each job? -- Do you
know if your printer uses "process control" during set-up and
running of your job ?
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Rick McCleary"
Wed Nov 21, 2007 5:59 am (PST)
On Nov 20, 2007, at 6:39 PM, Henry Davis wrote:
The observation above cannot be repeated often enough.
I believe
that the point Paul is making is unpopular with the
"calibrationist"
crowd,
... and what exactly, is a "calibrationist?"
I'm pretty sure I know where you're going with this, I just want to hear
you say it.
and I'll add that the misinformation that has been
perpetuated
has proved to be difficult to correct. It is assumed by
other
parties that may be less informed that the
"calibrationist" is
experienced and capable and thus has a very good
understanding of
presses and the variables of printing.
Again, how are you defining "calibrationist?"
If it's someone who buys a copy of ProfileMaker and hangs out a shingle,
I'd agree that they are not bringing much to the table. However, if it's
someone who sees the value of taking the entire workflow into
consideration, from image creation to dots on paper, I see that person as
the missing link.
Let me repeat again that I am not
"anti-profile" or "anti-color
management". On the other hand, I will also repeat
that profiles and
color management are not the "magic" that
they have been claimed to
be.
I think we have moved well beyond the "magic
bullet" theory of predictable color rendering. With many devices and
many operators, it's not "push-button" easy. But it's a lot more
accessible now than it was two years ago.
I agree with Paul that the word "calibration"
does not apply to a
printing press.
How about "process control?" How about
Gracol7? Call it what you want, but I know that I can deliver a file to a
Gracol7 printer anywhere in the country and get very predictable rendering.
The work done by color management scientists can be
useful. But
color management has also been misleading, and its
claims often lead
to misunderstandings. How many times have we been
cautioned that
"education" is the key. That designers must
be educated, yet, what a
designer hears is that color management has carried all
of their
worries away. After hearing this, how much education do
you think
that a designer will feel the need for?
Henry, I believe that you speak very eloquently for a
large group of printers and prepress folks who are frustrated by the
oversold promises of color management, circa 1998 (Photoshop v5.0, the
first step into the world of color management.) However, it's 2007 now.
Much has changed. There are systems in place that work amazingly well to
give predictable CMYK output on an entire range of presses.
After reading your post, I know what you're NOT in
favor of. I just have know idea what you're advocating. I look forward to
your thoughts.
Rick
RICK MCCLEARY PHOTOGRAPHY
201 Orchard Drive
Purcellville, VA 20132
v 540-338-4895
c 540-454-7180
www.rickmccleary.com
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Andy Adams
Wed Nov 21, 2007 5:59 am (PST)
So much for me not commenting on this subject
anymore...
Let me just say that first of all, worrying about what
terminology is correct is silly. It is like arguing over how to pronounce
tomato or potato. I mean, if I were to use the term "hot chick",
would someone try to argue that such a term should only apply to a baby
chicken with a high temperature?
That being said, everyone is making good points about
the instability of printing presses. Which makes me wonder, what the heck
is all the arguing over. All we are trying to do is create (through
calibrating, stabilizing, whatever) a press condition we can have some sort
of control over. I really don't care if we start using the term
"jacking up the press" instead of "calibrating the
press". If I can "jack up the press" better than than
someone else, that just means I have achieved (for the time being) a
narrower window of repeatability on press.
Granted, color management is not the panacea some may
promote. But is it something that needs to be done. Some just take it more
seriously than others. Which, hopefully, translates into better management
of their color capabilities. Some will use anything as an excuse not to
calibrate (there, I said the word) their press, while others will turn
calibration/color management into a religion.
Most of us just want to do the best job possible, while
others can't wait to argue. Which one are you or I? Just ask your boss, you
might just be unpleasantly surprised. As for me, I am going to keep
"jacking up the press" the best I can and within the workload
time constraints I am under while at the same time not giving a @#%! what
the heck it is called.
Andy Adams
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Jim Rich
Wed Nov 21, 2007 7:35 am (PST)
Henry,
Ahh....what the heck are you talking about here? Are
you suggesting your own private language or something much more
ridiculous???
If calibration and then color optimization was easy
then people would not have questions about it.
Using any type of calibration technology is really
about three things, understanding the technology, using skill and having
the right expectations. If you don't have either then you can fail.
It sounds like you and some others who buy into the
notion that gosh press calibration is so hard and confusing that perhaps we
should start calling people names or making up our own language or better
yet not even consider discussing it or something foolish like that.
Press calibration ain't easy and cheap. But it is
possible to accomplish. Just ask anyone who has been there and done that.
Or better yet you might want to visit another list like
the Printing Across Boarders or a Print Planet list and I suspect you would
have an eye opening experience to read about that press calibration and
using icc profiles is really possible.
If you don't want the words press calibration in your
vocabulary or as part of a belief system that is fine. Just don't ask us
folks who use color science, skill and common sense who calibrate and
profile presses not to discuss it because you might get confused.
Jim Rich
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Dan Margulis
Wed Nov 21, 2007 7:36 am (PST)
Andy Adams writes (and Rick McCleary similarly),
Let me just say that first of all, worrying about what
terminology is correct is silly. It is like arguing
over how to pronounce tomato or potato. I mean, if I
were to use the term "hot chick", would
someone try to
argue that such a term should only apply to a baby
chicken with a high temperature?
I agree with the above and suggest that an otherwise
useful thread is in danger of being derailed by a nitpicking discussion of
what "calibration" means.
From my POV everybody who has posted here is saying
much the same things--and this consensus would not have existed here five
years ago. Today everybody seems to be realistic about what the objectives
are and also what the limits of the process are.
I believe we would all agree on the following two
points:
*It is necessary for the persons responsible for press
operation to decide how the press *should* perform, and make efforts to
keep it performing that way in a stable fashion. This step is necessary
before anybody tries to profile anything. It is quite similar to the
approach one would take in calibrating a desktop printer or a monitor and
in this respect the word "calibration" may seem appropriate to
some.
*All those posting have correctly emphasized the need
for strict process control thereafter. If that is absent, the desired
stable state of the press--its calibration, if you will--won't last for
more than a few minutes. In this respect, the process is *not* like
calibrating a desktop printer or a moderator and thus it may seem sensible
to some to avoid the use of the word "calibration".
The discussion of these topics and their ramifications
are useful. Arguments over what a specific word means are less so.
Dan Margulis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Henry"
Wed Nov 21, 2007 11:11 am (PST)
Jim,
You are above this kind of rhetoric. One might even
believe this was aimed as an insult if they didn't figure that, well, this
thread just struck a nerve. I'll try to be more sensitive.
It also appears that you have made some erroneous
assumptions about me, and added to them some motives that I do not have.
You do not know what I have "bought into", so stop with the
insinuations already.
To clarify, I will repeat: I am not anti-profile, nor
am I anti-color management. But I am for honest and forthcoming discourse
on the subject. For this we are condemned to use words.
I have heard a great deal about the deltaE of this and
that. So, let me ask your opinion:
1. What deltaE is reasonable for a press, running 24/7
on different substrates, as compared to a monitor? This is a real-world
press, not one that you are temporarily setting up for printing profile
building patches.
2. Which one, the monitor or the press, would you
consider "calibrated"?
These are important questions. Prior to the print shop,
there is the creative who has expectations. A lot of them base their
expectations on their monitor. How is it that they are to understand the
acceptable differences, when they have been told that both devices are
"calibrated"?
Henry Davis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "John William Lund"
Wed Nov 21, 2007 11:11 am (PST)
Mr. Margulis,
Just wanted to thank you for your influence in keeping
this thread on a constructive course. As a lurker for the most part, I must
admit I do usually enjoy the humor in your sarcastic blasts, but I learn a
lot more from color theory discussion & people sharing hard-won
experience.
I have to comment on this, though:
In this respect,
the process is *not* like calibrating a desktop printer
or a moderator and thus
it may seem sensible to some to avoid the use of the
word "calibration".
-- Wow! Have you, as moderator, been
"calibrated" (should I say "adjusted"?) to refrain from
those entertaining rants about "calibrationists"? Can I imagine
Chris Murphy using an EyeOne Display on you? The mind boggles…
;-)
Regards,
John Lund
JWL Images
Emeryville, CA
2.8.
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Jim Rich
Wed Nov 21, 2007 12:23 pm (PST)
Henry,
First of all to set up a calibrated system you have to
know something about the components of a system and how repeatable the
system is. If the press looks like it is working correctly and therefore
can produce prints that fall within a reasonable tolerance during process
control checks then the press get calibrated etc.
Some form of delta e is a good guide for certain
aspects of color matching, but most all press operators use process control
tools such as density to monitor a press and often start with .05 density
as a tolerance for solid ink densities (SID). Midtones are often monitored
using a .02 or .03 tolerance.
But mileage here varies due to the cost to the printer.
Smaller tolerances are more costly, but the result is often higher quality
printing and vice versa.
It might be up to a consultant to guide a client as to
what value of tolerance to consider using but it is the process that
dictates what the actual tolerances will be. And of course the printer and
press crews have to use them. Those tolerances are usually (if your lucky)
assessed before any calibration or profiling takes place.
If you are asking if a monitor or a press can be
calibrated. Yes they can.
Can a monitor and a press sheet share the same
appearance if they are both kept under control after calibration. Yes. Is
is easy, nope.
Jim Rich
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Henry"
Wed Nov 21, 2007 4:10 pm (PST)
On Nov 21, 2007, at 3:10 PM, Jim Rich wrote:
If you are asking if a monitor or a press can be
calibrated. Yes
they can.
Can a monitor and a press sheet share the same
appearance if they
are both kept under control after calibration. Yes. Is
is easy, nope.
Assuming that there are colors being printed for a job
(besides the grey control patch), I still don't think I have an answer to
the first question. SIDs and mid-tones within tolerance aren't the whole
story. With regard to a colorful, real-world job, here is the question
again:
1. What deltaE is reasonable for a press, running 24/7
on different
substrates, as compared to a monitor? This is a
real-world press,
not one that you are temporarily setting up for
printing profile
building patches.
DeltaE can be due to a greater difference in hue alone,
so just describing the deltaE is less than an ideal way to communicate
these differences. Plus, deltaE doesn't really describe what is going very
well for people doing design work. A deltaE of 3 or 4 will appear more
noticeable in some colors than others. So, the question is one that I hoped
would speak to the issue of how we should communicate about color and
calibration.
As for the second question, the answer was the one I
expected. So I'll put it another way:
When there is a disagreement between the output of
calibrated press and a calibrated monitor, which one of the devices is
really calibrated? In my way of thinking, "both" might be
somewhat of a specious answer.
We are all disserved by misleading terms, whether it is
intentional or not. I have no clue for a better term, but there is a need
for one. Saying that two devices are calibrated to each other, but that one
can have a greater margin of error than the other, seems, um, sort of like
someone asking that you understand that they are hedging their bet in
advance. But any print job is somewhat of a gamble, eh?
Henry Davis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Henry"
Wed Nov 21, 2007 4:10 pm (PST)
On Nov 21, 2007, at 10:34 AM, Dan Margulis wrote:
I agree with the above and suggest that an otherwise
useful thread
is in danger of being derailed by a nitpicking
discussion of what
"calibration" means.
If it is nit-picking, then here is the nit that I am
picking:
When one uses the word "calibration" to
describe two different devices that are to be used together, there is and
implication that the two devices are in agreement, that they have been
brought to a level of exact agreement.
Two speedometers that are calibrated will be in perfect
agreement. A monitor and a press, thought "calibrated", will not
be in perfect agreement, so why continue to use a word that presumes such a
thing?
The word implies precision, especially to the layperson
or print-buyer.
Now, to my knowledge, there has yet to appear on this
list a demonstrably effective way in which the differences between two such
calibrated devices can be communicated, other than a reference to deltaE.
There has not been a practical method proposed that would illustrate such
differences, yet, if the press is calibrated, well, that word says it all.
Hogwash.
As an educator, I challenge you to "educate"
the creative or print-buyer using deltaE - without their eyes glossing
over. I'll bet that, without using visual aids, you would find that such an
approach would bear little fruit with that audience. Yet, these are the
very people who understand that when devices are calibrated, they are in
agreement.
Henry Davis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: murphychris2002
Wed Nov 21, 2007 4:10 pm (PST)
Quoting Henry <hd@imagers.com:
The observation above cannot be repeated often enough.
I believe
that the point Paul is making is unpopular with the
"calibrationist"
crowd, and I'll add that the misinformation that has
been perpetuated
has proved to be difficult to correct.
Like the misinformation that presses aren't
controllable? That you cannot establish some baseline of behavior, with
tolerances, and a rational interval for maintaining that behavior? Well
this is what's been proposed by people who whine and complain about how
color management doesn't work. It's completely specious. When you peel back
the onion, what is nearly always the case is the printer has near
non-existent process control measures in place.
It is assumed by other
parties that may be less informed that the
"calibrationist" is
experienced and capable and thus has a very good
understanding of
presses and the variables of printing. There are
probably some
reading this thread that are of the belief that a press
can be
calibrated - mainly because this is what they would
like to hear, and
also because they are being told that this is the case
by folks who
are tops in the color management field.
No mainly because it has actually been done, not due to
wishful thinking. The denotation of the word calibrate means slightly
different things in different contexts, and certainly in the context of a
printing press it is not the same level of precision or accuracy as what
you'd use to calibrate an altimeter in an airplane. But can you make a
press repeatable within a reasonable tolerance? Yes. Can it be done today,
tomorrow, next week? Yes it can.
Let me repeat again that I am not
"anti-profile" or "anti-color
management". On the other hand, I will also repeat
that profiles and
color management are not the "magic" that
they have been claimed to
be.
Strawman.
What have they claimed to be? By whom? What is this
magic? Under what conditions? Was there some explicit or implicit
suggestion that color management works in all instances regardless of how
poorly devices behave? Cite the source.
There isn't a creative or layout designer in the world
that
wouldn't like to hear that color accuracy is no longer
a guessing
game, that these problems have all been solved.
Most designers wouldn't know an accurate proof if it
hit them in the head. They routinely demand of their service bureaus to
produce proofs on insanely bright white paper stocks that have no
correlation to what will be used on the final job. They routinely specify
spot colors when
they have no intention of printing with them, but
intend to print CMYK.
Most designers say they want accurate color. But when
given the option, clearly demonstrated matches between proof and press
sheet, what they would show to their customers is the bright white,
saturated, high contrast version. What do they say to the response that
this isn't accurate? "Well it looks better and that's what the
customer wants." You can ask them ultimately "so you're saying
the customer wants to be lied to?" And they say, "well, yeah,
they probably won't see the final printed piece anyway, they just see the
proofs."
So then ad agencies send people out on press checks
demanding all these odd ball changes on press, to deal with improperly
prepared files, designed to make proofs look good and not print properly.
And that in turn is in direct contrast to printing to a printing
specification, the sole purpose of which is to calibrate the press to a
known reference point and make it consistent.
If only the
proponents had been as forthcoming with all of the
things that
profiling and color management could not solve, or
weren't designed
to solve, we would now have a much smaller tiger by the
tail. I
agree with Paul that the word "calibration"
does not apply to a
printing press. This word is overloaded with meanings
that do not
apply to a press - but it does tickle the ear of those
who don't want
to be confused by the facts.
You are entitled to your own opinions. You are not
entitled to your own facts. Merely saying something does not make it true.
Calibration frequently is not applicable to printing
presses because the printer can't tell you what inks are in his press, what
specification they conform to, what the in-house target ink densities (or
LAB values) for cyan, magenta, yellow, black are. He can't tell you what
dot gain is. He will say he makes things work, and that is the ONE thing
that is absolutely correct. But it's with a hammer that things work. And
that is certainly in contrast to process control, calibration, and
conforming to applicable print specifications.
But there are very good printers in the world and in
this country who actually have a densitometer that's charged, recently
certified, and surprise, surprise, is actually used in the pressroom to
measure, confirm, modify - in order to maintain press behavior to
established aim points.
Saying that a press cannot be calibrated when in fact
they can be, just because there is such a large percentage of crummy
printing and process control is totally ridiculous because it's so easily
demonstrated to be false.
Oh, but when pinned down, even the
"calibrationist"
will back-peddle and say that there is no such thing as
a perfect
color match, and may even admit that there are other
unfulfilled
promises. But this admission is only offered when it is
forced - and
this is misleading.
Qualifying a statement is back-peddling? And you have
the audacity to talk about scientific terms at all when you're clearly
attributing politically charged language and straw mans under the disguise
of an intellectual conversation?
I wonder if I could calibrate a watch to the timing of
this list because it seems like it's almost exactly a 6 month interval when
someone comes on the list and starts up with the "calibrationist"
play-ground name calling. It is after all intended to be amusingly
condescending first and foremost. Where's Andrew to tell it like it is? Oh
right, he's been kicked off the list.
This doesn't mean that a "general" profile
isn't possible. A profile
is a description of a press in a certain state. But,
the fact
remains that a press and the printing that comes out of
it is almost
necessarily variable. A printing press is not a
"calibratable"
machine. It isn't stable enough for a snapshot to offer
a precise
portrayal, and a profile would more reasonably be
offered as
something that can be used as a general guide. For
argument: If a
digital camera can't be precisely calibrated for
outdoor use, how can
a printing press?
What you've totally failed to grasp is the tolerance.
Everything that is calibrated has a tolerance within which it is considered
calibrated and outside of it is not calibrated. You are seemingly applying
an unreasonable tolerance to the behavior of presses, and thus charging
them as lacking sufficient stability when you haven't even qualified the
stability you think is required. YOu're just making statements as though
they are fact, but you're completely wrong.
The work done by color management scientists can be
useful. But
color management has also been misleading, and its
claims often lead
to misunderstandings. How many times have we been
cautioned that
"education" is the key. That designers must
be educated, yet, what a
designer hears is that color management has carried all
of their
worries away. After hearing this, how much education do
you think
that a designer will feel the need for?
Go look at the typical ad agency retouching environment
and compare that to the typical competent pre-press retouching environment.
Designers have been told until everyone is blue in the face about how you
can't do the things they say they want to do in a room full of windows and
bright lighting that changes every 10 minutes. Guess what? It's
disqualifying.
It has even gotten to the point now that more
"boutique RGBs" are
popping up. I don't mean JoeRGB or Bruce RGB, but
"ABC Printing Co
RGB" and "XYZ Printing Co RGB", along
with the "XYZ Photo Agency
RGB", are beginning to muddy up the waters even
more. Isn't the
presumption here that a "Custom" RGB offered
by a printer or agency
is a "better" editing space or a "more
calibrated" solution?
It's probably harmless, but it might not be without
more scrutiny and testing. I think it's pretty laughable that any company
would be coming up with their own RGB space. I'd say at best a custom RGB
space is a hack for some other problem they've encountered and they think
this solves it, but chances are it's just snake oil.
Chris Murphy
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Henry"
Thu Nov 22, 2007 5:17 am (PST)
On Nov 21, 2007, at 4:10 PM, Chris Murphywrote:
Like the misinformation that presses aren't
controllable? That you
cannot establish some baseline of behavior, with
tolerances, and a
rational interval for maintaining that behavior? Well
this is what's
been proposed by people who whine and complain about
how color
management doesn't work. It's completely specious. When
you peel back
the onion, what is nearly always the case is the
printer has near
non-existent process control measures in place.
Whoa, and hold on a minute. You go too far. I have
never, ever said that a press isn't controllable. If one cannot point out
the shortcomings of color management without becoming the target of these
kind of knee-jerk remarks from its proponents, then I think one can see
where the thin skin really is. I have always said that color management can
be useful as well as stating that I am not anti-profile. I am not
anti-Chris, or anti-anybody on this list. So I
hope that you aren't including me in the above
innuendo.
No mainly because it has actually been done, not due to
wishful
thinking. The denotation of the word calibrate means
slightly
different things in different contexts, and certainly
in the context
of a printing press it is not the same level of
precision or accuracy
as what you'd use to calibrate an altimeter in an
airplane. But can
you make a press repeatable within a reasonable
tolerance? Yes. Can it
be done today, tomorrow, next week? Yes it can.
Again, you have assigned to me something that I haven't
claimed.
Let me repeat again that I am not
"anti-profile" or "anti-color
management". On the other hand, I will also repeat
that profiles and
color management are not the "magic" that
they have been claimed to
be.
Strawman.
Straw man? Take a look at your reply. You allow the
word "calibration" to have an imprecise meaning, while the
application of the meaning of the word itself is being debated. There's a
humorous irony here too.
You are entitled to your own opinions. You are not
entitled to your
own facts. Merely saying something does not make it
true.
I think that this post of your very own opinions about
most designers gives credence to how misunderstandings about the subject
have been occurring for the past decade and a half or so. There are some
ridiculous misunderstandings, aren't they? But, alas, designers are in the
loop.
Saying that a press cannot be calibrated when in fact
they can be,
just because there is such a large percentage of crummy
printing and
process control is totally ridiculous because it's so
easily
demonstrated to be false.
A press can be made to perform within certain
tolerances. My concern is the word that is used to describe these
tolerances. I think you will agree, won't you, that "conform" and
"calibrate" are different in meaning?
Qualifying a statement is back-peddling? And you have
the audacity to
talk about scientific terms at all when you're clearly
attributing
politically charged language and straw mans under the
disguise of an
intellectual conversation?
Yes, qualifying a statement can be considered
back-peddling. And, if you think that I am trying to "disguise"
my input to the list as either "scientific" or
"intellectual", you are mistaken.
What you've totally failed to grasp is the tolerance.
Everything that
is calibrated has a tolerance within which it is
considered calibrated
and outside of it is not calibrated. You are seemingly
applying an
unreasonable tolerance to the behavior of presses, and
thus charging
them as lacking sufficient stability when you haven't
even qualified
the stability you think is required. YOu're just making
statements as
though they are fact, but you're completely wrong
It is not me that is applying an unreasonable tolerance
to a press. And, you are correct, I haven't qualified the stability that I
think is required. I have asked about this, though.
Go look at the typical ad agency retouching environment
and compare
that to the typical competent pre-press retouching
environment.
Designers have been told until everyone is blue in the
face about how
you can't do the things they say they want to do in a
room full of
windows and bright lighting that changes every 10
minutes. Guess what?
It's disqualifying.
It is a sad "fact" that some people just
don't behave as they ought. When an agency is consulted that they must do
this, and this, and this, and the other thing as well, they probably do
find it to be a hassle. But they all want to know if the press is
"calibrated", as if that is the end of it, as if that word says
it all.
It's probably harmless, but it might not be without
more scrutiny and
testing. I think it's pretty laughable that any company
would be
coming up with their own RGB space. I'd say at best a
custom RGB space
is a hack for some other problem they've encountered
and they think
this solves it, but chances are it's just snake oil.
It may be harmless, but in the not so distant past, I
seen to recall that one of the main concerns was over there not being a
"standard" RGB. It may be laughable, but such things have a way
of catching on, especially as a marketing ploy. It would be amusing to see
how many boutique RGBs come into being.
Henry Davis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: murphychris2002
Thu Nov 22, 2007 5:17 am (PST)
Quoting Henry:
Two speedometers that are calibrated will be in perfect
agreement. A
monitor and a press, thought "calibrated",
will not be in perfect
agreement, so why continue to use a word that presumes
such a thing?
Umm, well the obvious seems to apply here. In the first
case you\'re comparing two instruments that purportedly serve very similar,
if not identical tasks. A display and a press are completely different
things. They have their own natural variation and their own optimized
behaviors. So naturally the procedure, interval, and tolerance for
calibrating a display will be different than that of a press.
The word implies precision, especially to the layperson
or print-buyer.
Yes it does and if you read the definition of
precision, by itself it is inherently relative. What is sufficiently
precise in one context is not in another.
There is such a thing in instrument flying called
non-precision approaches, and precision approaches. The primary
differentiating factor is glideslope, rather than stepped down descent
based on distance from a fix, a precision approach expect you to be in a
particular place in 3D space.
And the precision of the precision approach is
variable. It is not consistent.
And the precision of the precision approach is still
measured in meters which is a lot less precise than what is needed to park
a car.
And just because I can park a care with greater
precision, in terms of inches instead of meters, does not mean the
precision approach is not precise, or is improperly labeled. It is a matter
of function, and context.
Now, to my knowledge, there has yet to appear on this
list a
demonstrably effective way in which the differences
between two such
calibrated devices can be communicated, other than a
reference to
deltaE. There has not been a practical method proposed
that would
illustrate such differences, yet, if the press is
calibrated, well,
that word says it all. Hogwash.
Calibration is and has always actually meant to apply
to the device itself, in relation to something designed for
measuring/verifying the behavior of that device to an applicable reference.
It is an improper but common use of language even today to talk about
calibrating a monitor to a printer or vice versa. This is, of course, not
possible.
It is possible to compare particular colors produced on
these two very different devices and quantify their apparent color
difference in terms of a number that kinda sorta makes sense, and we do
have to be careful with what DeltaE is being talked about and what its
limitations are. They all have limitations.
It's hogwash to say and keep saying that presses cannot
be calibrated. It is truth to say they generally are not calibrated.
As an educator, I challenge you to "educate"
the creative or print-
buyer using deltaE - without their eyes glossing over.
"Smaller number, closer color match." Most
people will understand that. In general that is true with all Delta E,
although it is much more meaningful using more modern delta E formulas. I'd
characterize Delta E ab as being next to useless.
I'll bet
that, without using visual aids, you would find that
such an approach
would bear little fruit with that audience. Yet, these
are the very
people who understand that when devices are calibrated,
they are in
agreement.ions of this message have been removed.
They're misinformed. It's not an uncommon problem.
Chris Murphy
___________________________________________________________________________
Re: Press profiles, use of
Posted by: J Walton
Thu Nov 22, 2007 5:17 am (PST)
On Nov 21, 2007 12:19 PM, Henry wrote:
When one uses the word "calibration" to
describe two different
devices that are to be used together, there is and
implication that
the two devices are in agreement, that they have been
brought to a
level of exact agreement.
No. That is not true. What is true is that Dan has
become sort of a prophet, and has predicted this conversation would take
place before you replied to his post. My prediction is that this post will
not go through, but I've been known to be wrong.
Two speedometers that are calibrated will be in perfect
agreement.
No. That is not possible in any way whatsoever. They
may be so close that you can't with your eye or a measuring instrument tell
the difference, but there is always some sort of tolerance involved. There
is no such thing as perfect agreement, as our little email list constantly
demonstrates.
A monitor and a press, thought "calibrated",
will not be in perfect
agreement, so why continue to use a word that presumes
such a thing?
Because that word does not mean what you think it
means.
The word implies precision, especially to the layperson
or print-buyer.
Yes, that's true. But precision and perfection are two
different things. There always has to be a tolerance of some sort. Some
clients are very tolerant, some are very picky.
Now, to my knowledge, there has yet to appear on this
list a
demonstrably effective way in which the differences
between two such
calibrated devices can be communicated, other than a
reference to
deltaE. There has not been a practical method proposed
that would
illustrate such differences, yet, if the press is
calibrated, well,
that word says it all. Hogwash.
It's as if you feel the goal of calibrating is simply
making certain numbers match. The point of calibrating a monitor and doing
the same for a press is so that the most important measuring tool, your
eyes, don't really notice a significant difference. That's the tolerance.
As an educator, I challenge you to "educate"
the creative or print-
buyer using deltaE - without their eyes glossing over.
I'll bet
that, without using visual aids, you would find that
such an approach
would bear little fruit with that audience. Yet, these
are the very
people who understand that when devices are calibrated,
they are in
agreement.
A fruitless exercise if I ever heard one. Have you MET
a print buyer lately? When these people hear that a device is calibrated,
they understand that the company they are dealing with has their act
together. That's all they understand.
--
J Walton
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Richard Wagner"
Thu Nov 22, 2007 5:17 am (PST)
On Nov 21, 2007, at 1:19 PM, Henry wrote:
>
When one uses the word "calibration" to
describe two different
devices that are to be used together, there is and
implication that
the two devices are in agreement, that they have been
brought to a
level of exact agreement.
Nope. That's an erroneous assumption on your part. To
take a relevant example, your monitor can be calibrated, and your Epson
printer can be calibrated, yet they will not be brought into "a level
of exact agreement" because their gamuts are different. You're
comparing apples and oranges and trying to say they're the same. Certainly
the device numbers will be different. Try assigning a printer profile to an
image that is in a standard working space - the color will be off, because
even though both devices may be calibrated, the image numbers need to be
translated from the working space into the printer space for the image to
print correctly. "Exact agreement" between different types of
devices doesn't exist. That's why ICC color management developed in the
first place.
Two speedometers that are calibrated will be in perfect
agreement. A
monitor and a press, thought "calibrated",
will not be in perfect
agreement, so why continue to use a word that presumes
such a thing?
Each can be independently calibrated - i.e., brought
into a known state. Has nothing to do with being "identical."
Your understanding of the word "calibrate" is in error. And you
haven't even made the transition from calibration to profiling and mapping
between different color spaces.
The word implies precision
That's what happens when people don't understand and
misuse terminology, and that's why many of us respond when standard
terminology is misused. Having a perfectly calibrated monitor and press
says nothing about how well an image will print. The colors in your image
may be in gamut on your monitor, and completely out of gamut on press, even
though both are calibrated. If you use the word calibrate to imply a match
between different devices, you don't understand color management.
Now, to my knowledge, there has yet to appear on this
list a
demonstrably effective way in which the differences
between two such
calibrated devices can be communicated, other than a
reference to
deltaE. There has not been a practical method proposed
that would
illustrate such differences, yet, if the press is
calibrated, well,
that word says it all. Hogwash.
I don't recall anyone saying that if a press is
calibrated that "that word says it all." Color output devices are
compared not by "calibration" but by a device-dependent color
space, commonly referred to as an ICC profile. There are a lot of tools for
doing this, with the most notable being ColorThink, where you can take any
color from one device space and map it into another device space. You can
easily see if colors are in-gamut and capable of being printed accurately,
or out-of-gamut, where they will need to be mapped to another color.
Calibration is merely a prerequisite to profiling. If using a RIP on a
printer, this re-calibration is called linearization - it brings the
printer back to a known state. The new HP printers actually have a
spectrophotometer built-in to do this. Printing presses traditionally have
used densitometry. It's nothing new, but the tolerances are getting tighter
and tighter, and there is far more automation than there used to be.
On-press "color correction" is the bane of printing. Presses
should be "run to the numbers" and then they are very
predictable. Yup, then they're calibrated.
As an educator, I challenge you to "educate"
the creative or print-
buyer using deltaE - without their eyes glossing over.
You don't need to use Delta-E to educate creatives or
print-buyers. I find that 3-D gamut maps work a lot better (and they're in
LAB!). Show them that a press can't print certain colors, NO MATTER WHAT,
and they then realize that they shouldn't use those colors, because they'll
get mapped to something else. It's not rocket science.
I'll bet that, without using visual aids, you would
find that such an approach
would bear little fruit with that audience. Yet, these
are the very
people who understand that when devices are calibrated,
they are in
agreement.
Nope, these people realize that different devices have
different gamuts, and even when everything in the workflow is calibrated,
you can't push a square peg into a round hole. Scanners, monitors, inkjet
printers, and printing presses have inherently different gamuts. All can be
calibrated. All can be profiled. To communicate between these devices, you
need to use ICC profiles to translate the device numbers from one device to
another, using the profile connection space. Some numbers just won't
translate, because they're out of range for a given device. That's color
management in a nutshell.
--Rich Wagner
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Thu Nov 22, 2007 9:55 am (PST)
He he,
Looks like an "ALARM" went off...
If people did not care about terminology, why would
they react to word "calibration", which might also be called
"hot chick" by one poster? Maybe "calibration" is
"hot"? :-)
From the GRACol7 specification information:
Realistic Expectations:
Remember that offset printing is typically much less
consistent and uniform than a typical proofing system . Even the best press
operated by the most experienced workers under ideal conditions can vary
considerably from run to run, due to small changes in materials,
temperature, humidity, length of run, etc . The chances of a
Œperfect©ˆ press sheet from any particular offset press run
are very small .
The goal of G7 press calibration is to adjust the plate
curves so that on an average day an average press run will come very close
to simulating the ideal G7 NPDC and gray balance, but remember that most
presses will deviate somewhat from the target values most of the time .
Too bad the publication needed the "buzzword"
as only plate curves have to be introduced/adjusted to get a
"standardized printing condition" within tolerances.
In all this rumble the main topic got lost:
Standardization versus customization.
When most printers would follow the IDEAlliance
guidelines and specifications for standardization, communication could
become less complex.
The call for more profile generation by the "you
know-ists" called "press-profiles" undermine in a severe way
the work of the "IDEALlists"
I hope that in the next errata to the guidelines, the
terminology will get fixed. I like the terminology "process control
kit" or "standardization guidelines".
From the G7 guidelines:
Print buyers need to understand that printers offering
to print ©¯better©˜ than a specification such as GRACoL
2007 or SWOP 2007 may well be able to do so, but files and proofs generated
by that printer may not be interchangeable with another printer, and
vice-versa, without careful color management.
Thanks for your attention!
Paul Foerts
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Thu Nov 22, 2007 9:53 am (PST)
Richard Wagner wrote:
Other than the "3 minute fix" from those with
expertise in color
management, I haven't seen any other good solutions to
the original
problem posted here.
Richard, perhaps you missed the solution that I came up
with and mentioned at least twice, right before Terry and Peter offered a
more ideal solution? I did not get any feedback, but I thought it was a
good solution considering that I did not have access to profile editing or
[re]generation software and only had Photoshop.
Only one print setting that I have worked for has had
the required hardware and software for creating profiles. All print shops
that I have worked for have had Photoshop (even back when Scitex and other
proprietary graphics systems ruled, they had Photoshop).
My earlier conversion workflow suggestion handled the
problem OoG rendering issue of reds/greens and provided visually near
identical results to the profile generated by Terry, with device numbers
that were a great improvement over the standard "conventional
wisdom" workflow conversion results.
All using the poor Midas profile for the final
conversion. No more OoG rendering issues (but I was stuck with the total
ink limit without adding further post transform steps). I didn't have
access to the tools that Terry and Peter did. I only had Photoshop.
The new profile provided by Terry was the better method
of the two, it only has to be done once and offers better device numbers.
Without access to such resources, my method provided the best result for a
user that only has Photoshop. It is simple, flexible, fast (depending on
file size) and can be actioned and batched (only 2 or 3 steps).
I don't have time to dig up the post references at this
point.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "dbernaerdt"
Thu Nov 22, 2007 10:02 am (PST)
As I have a spare couple moments -
Stephen's post quoting the 2 step workaround is message
#18804 (Tues, Nov 6) for those wishing clarification.
Darren Bernaerdt
___________________________________________________________________________
Re: Press profiles, use of
Posted by: remaleydan
Fri Nov 23, 2007 8:51 am (PST)
Here's my question about G7 (from below). If I had a
printed sheet in front of me how would I 'know' that it was printed
"within specification"? Under the older SWOP standard I could
read a color bar and determine if the density, or midtone dot gain was was
correct, or within specification. Brunner says 80% of color deviation comes
from dots only 20% from solids. Dan Remaley
Original Message:
-----------------
From: Paul Foerts
From the GRACol7 specification information:
Realistic Expectations:
Remember that offset printing is typically much less
consistent and uniform than a typical proofing system .
Even the best press operated by the most experienced
workers under ideal conditions can vary considerably
from run to run, due to small changes in materials,
temperature, humidity, length of run, etc . The chances
of a Œperfect©ˆ press sheet from any
particular offset press
run are very small .
The goal of G7 press calibration is to adjust the plate
curves so that on an average day an average press run
will come very close to simulating the ideal G7 NPDC
and gray balance, but remember that most presses will
deviate somewhat from the target values most of the
time .
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Chris Murphy
Fri Nov 23, 2007 8:54 am (PST)
On Nov 21, 2007, at 6:50 PM, Henry wrote:
Whoa, and hold on a minute. You go too far. I have
never, ever said
that a press isn't controllable.
So a press is controllable? And yet it cannot be
calibrated?
If one cannot point out the
shortcomings of color management without becoming the
target of these
kind of knee-jerk remarks from its proponents, then I
think one can
see where the thin skin really is.
Where are you talking about color management? You've
stated, as fact, that presses can't be calibrated. That is easily proven
false.
Straw man?
Yes. Straw man. As in, you have proposed a foolish
argument (profiles and color management are magic), made by undisclosed and
uncited sources, and then said they're really not magic. Well, duh. So
that's called a straw man.
And in response to five questions and an invitation for
you to clarify what has been claimed and by whom and the context, you
presented nothing.
Take a look at your reply. You allow the word
"calibration" to have an imprecise meaning,
while the application of
the meaning of the word itself is being debated.
There's a humorous
irony here too.
Calibration has rather specific meaning. I'm unable to
allow it to have an imprecise meaning, I don't even know how I'd go about
doing that. I don't have the power to rewrite dictionaries or change the
denotation of words.
I think that this post of your very own opinions about
most designers
gives credence to how misunderstandings about the
subject have been
occurring for the past decade and a half or so. There
are some
ridiculous misunderstandings, aren't they? But, alas,
designers are
in the loop.
This is a complete non-response to your claim that
calibration does not apply to a printing press.
It is a sad "fact" that some people just
don't behave as they ought.
When an agency is consulted that they must do this, and
this, and
this, and the other thing as well, they probably do
find it to be a
hassle. But they all want to know if the press is
"calibrated", as
if that is the end of it, as if that word says it all.
That's because they're often confused about two things:
1. What calibration means.
2. That there is a single flavor of CMYK on the planet,
which if that were true, you could conceivably have a calibrated press and
that's all that would be required.
It may be harmless, but in the not so distant past, I
seen to recall
that one of the main concerns was over there not being
a "standard"
RGB.
Main concerns by whom? Why was it a concern? I don't
understand the relevance of this at all.
Chris Murphy
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Terry Wyse"
Fri Nov 23, 2007 2:49 pm (PST)
On Nov 22, 2007, at 6:52 PM, dremaley wrote:
Here's my question about G7 (from below). If I had a
printed sheet
in front of me how would I 'know' that it was
printed "within specification"?
The G7 spec keys on midtone 3-color gray balance and
visual density. The specification for G7 on coated stock would state that
midtone 3- color gray (50c40m40y) would measure .54 density above paper,
+/- .02. Neutrality should be around +/- .03 for "All filters"
(RGB) density. There's also secondary measurements for highlight and shadow
range as well.
Under the older SWOP standard I could read
a color bar and determine if the density,
or midtone dot gain was was correct, or within
specification.
Brunner says 80% of color deviation comes from dots
only 20% from
solids.
Which is EXACTLY why the G7 method keys on highlight,
midtone and shadow tone response and gray balance via "NPDC" or
Neutral Print Density Curve as opposed to placing too much emphasis on
solid ink density. In fact, G7 uses colorimetry (L*a*b*) for specifying
100% solids as opposed to ambiguous Status T density values. Any stated SID
values in the G7 2007 specification are either used as informative or
historic values.
I'm still a bit surprised that you continue to quote
single color dot gain or TVI values when you are, in fact, a major
proponent of running a press to gray balance. Wouldn't the G7 method be a
nice fit in this case? The G7 method uses a combination of midtone density
for tonality, which is directly related to dot gain or TVI, and midtone
gray balance as a technique for press control. Seems to me it offers the
best of both worlds (TVI and gray balance).
And you can still use TVI as a *process control* method
but it's not necessarily a good metric for assessing a visual or
"appearance"-based match between proof and press sheet or even
between different printing processes. Since TVI and SID do not translate
well between press and inkjet proofs, which are so prevelant today, we need
to use metrics that are meaningful for both. Colorimetry and the G7 specs
accomplish this in my opinion.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Jim Rich
Fri Nov 23, 2007 3:03 pm (PST)
Dan R.
This sure sounds like a trick question.
Perhaps not.
Your comments and question seem like a road side
advertisement for the old chain store on highways called STUCKY's or in
your case for GATF.
But if I have this wrong and you are serious and trying
to figure this out for yourself perhaps there is a better question to ask
that is not so pointed at hiring a consultant or selling a training
solution.
How about, what is GCR and how can it be used to make
4-color printing more consistent? Or if you use GCR then there is less of a
chance of color deviation. Or something along those lines.
Mileage will vary.
Jim Rich
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Dan Margulis
Fri Nov 23, 2007 3:03 pm (PST)
Howard writes,
All of which brings me to wanting to ask Dan how he
approached his book
printing. We know that he took his bedroll and moved
into the printing
establishment so he could supervise everything from
start to finish, and we
know that he got the results he wanted. Or at least he
hasn't said
otherwise. So, how about it, Dan? Did you go to some of
the extremes that
have been discussed here over the months, or did you
select a standard
profile, tweak it, prepare proof prints, then work with
some good printers
to be sure that they were giving it their best shot?
Neither, but I am not a particularly good model as a
client. OTOH, the experience may be of interest to some who wish to know
what the "real world" is like.
First of all, I've had a lot of experience with general
commercial printers, and also printers who specialize in magazines. Until
recently when they've gotten a lot better, printers who specialize in book
printing have usually been of much lower quality. Book publishers are
always looking to save a buck, and their production departments are
typically not sophisticated. This is a recipe for poor quality
expectations. Process control is expensive and most book printers weren't
doing nearly enough, again until recent days.
My six titles have been printed by five different
firms. Of these, only the one responsible for the printing of Canyon
Conundrum and PP5E had acceptable process control by commercial standards.
All but one of these books was reprinted at least
once--same printer, same press, same paper. In the first four editions of
Professional Photoshop, there was not much resemblance between the initial
run and the reprints. Jim Rich has offered some suggested tolerances for
density variation that he thinks are achievable for commercial printers.
The variations in these first four books were routinely 10, even 15 times
that.
It may seem unfair, but that's how the world is.
Products where color is critical (and color correction texts qualify, I
think) are printed by printers chosen in a process we have little control
over, and then if they (predictably) mess up, we get blamed. Yet, somehow,
this system can be made to work--even without proofs. I didn't pull proofs
for any book prior to PP4E because I felt they weren't needed and because
they were very expensive at that time. Plus, they don't serve the usual
purpose of giving the client the option of demanding a remake if the proof
isn't matched. In the case of a trade book, the client is the publisher,
not me. They aren't going to reject *anything* for printing short of a
total disaster.
By 2002 the proofing costs were much more manageable,
so for my last three books, I've gang-proofed the important sets of images
on 24x36 sheets. The purpose is not to check color so much as to see how a
group of images work together. In my books, I often run a series of four or
more versions of the same image on successive pages. I don't need a proof
to see whether any image is good by itself, but it's hard for me to
visualize how they work as a unit based only on monitor preview. Also, I
have the bad habit of sticking the wrong picture into the wrong layout,
which is tough to see without a hard proof.
PROFILING.
My approach to a printer I don't have experience with
has been the same for more than 20 years.
*Ascertain whether it is likely that the printer is
fairly consistent or whether there will be a lot of variation.
*Find out whether the printer has any information that
might aid in preparing the files.
*Find out whether anybody in the printing company knows
enough about prepress to be of assistance.
*Having gathered what information I can (which is often
pretty sketchy) make a tentative profile or use an existing one, being
ready to modify it as more information becomes available.
With respect to the first four printers of PP and the
fifth who did Makeready, I got copies of books they had printed plus (by
under-the-table arrangement with the boys in the back room) copies of some
of the digital files printed in said books, plus a sample of the stock to
be used in my book so that I could compare it to the printed books and
estimate the difference in dot gain. This is enough information to create a
good profile using Custom CMYK. None of the printers of my books had any
handouts available suggesting settings for files. The prepress department
of the printer of PP4E knew what an ICC profile is, but the press
department did not, and neither did any of the other printers, including
the printer of PP5E and Canyon Conundrum.
In fact, though, the profiles I made were not
"accurate" in the sense of the ones made by the color consultants
on this list, because I knew in advance that my printers suffered from poor
process control. The profiles were defensive ones aimed at reducing the
possibility of a really bad result, while conceding a slight inaccuracy if
the file is printed correctly.
For Canyon Conundrum, the circumstances were different
because first, I had reason to think that this was a printer who had good
quality-control procedures and could be relied upon to achieve consistent
results, Second, being a book about LAB, the idea was that there would be
no corrections in CMYK at all, and only limited ones in RGB. I wanted to
use "consensus" settings for each, and the obvious
"consensus" CMYK in mid-2005 was SWOP v2. So I put together a
sheet of sample images separated with SWOP v2 and asked the printer to
proof them, to see whether the results would be satisfactory. With the
exception of files featuring deep blues or near-blue neutrals, they *were*
satisfactory, so that's the profile I used, except for the Sierra Trading
Post blue jacket, where SWOP v2 is not capable of delivering the desired
CMYK mix. In this case, rather than use SWOP v2 followed by a Selective
Color move in CMYK, I chose to use my PP4E profile.
For PP5E, the printer was the same, but it was not
feasible to use SWOP v2 throughout because of the large amount of CMYK
correction being shown. In view of my previous luck with SWOP v2, I used
that for all images *except* those involving extensive CMYK correction or
deep blues.
THE PRESS CHECK.
Color correction on press should be a last resort. When
a client orders up extensive color changes during a press check, there are
really only three possibilities:
a) The printer is incompetent;
b) The client-supplied files were prepared
incompetently;
d) The client has a psychological need to feel
self-important or to justify his travel to the printer.
Accordingly, my roles at the pressruns of PP4E on the
one hand, and Canyon Conundrum and PP5E on the other, were entirely
different.
In the first case, although the printer had a
SWOP-certified proofing system, they couldn't match it on press. They had
rudimentary color bars (solids only) but were not reading them for
density--everything was "eyeballed". If they *had* been reading
the color bars and adjusting, it wouldn't have mattered. They didn't have
uniform blanket pressure across the form, so that dot gain was much higher
in the middle of each sheet than on the sides. Thus, a picture's appearance
could be drastically different depending upon where on the form it fell.
In that kind of lamentable circumstance there isn't
much to do except continually juggle inkflow to try to make the images
"look better". It is not a sport for the timid. If the client is
comfortable doing this, or if the pressman is exceptionally artistically
inclined, reasonable results are possible.
In the second case, not only were there valid color
bars, but they were continually being evaluated by a scanning densitometer
which revised ink flow on the fly. The pressman still has to remain alert
to a number of factors and adjustments are still necessary but the type of
wild improvisation of the first case is not required. In Canyon Conundrum
I'd guess I asked for half a dozen alterations in inking out of hundreds of
images total. In PP5E I can only think of two. One was my fault--I just
decided that a fleshtone image, even though it matched the proof that I had
marked as OK, needed some extra magenta ink. The other was nobody's fault:
the first image of Chapter 20 featured undersea life, prominently some
mussels that the text described as having a slight blue sheen. A black that
is only very slightly blue is a difficult color to achieve on press. It's
subtle enough and uncommon enough to challenge any method of color
management. We can't be surprised when it requires special handling on
press and simple ink balancing isn't enough.
In a press check a knowledgeable client, being more
familiar with the desired result than the pressman is, can identify
problems faster. In PP4E a bolt became deformed during the pressrun,
resulting in excessive bounce in one of the black cylinders. This caused
elongated dots and the appearance of a dot gain of around 50% in the black
plate. Since I use a skeleton black in color images, such an event is not
obvious unless you look for it, and the pressman had no proofs of grayscale
images such as individual channel grabs. These channel grabs are often
*supposed* to be very dark. When I saw one that was clearly so wildly
darker than what I knew it to be that it could not be explained by bad
inking, I stopped the run. Had I not been there, the pressmen would
eventually have realized that there was something seriously wrong with the
press but it might have taken them several thousand--or tens of
thousands--impressions before they caught it. And book printers don't throw
away such defective sheets--they wind up in somebody's copy of the book.
The pressroom is a noisy place and communication is
difficult--you have to shout. If a client understands how the press works
it is ever so much quicker to just scream out "MORE BLUE ZONE C"
than it is to explain that there seems to be a lack of detail in one of the
four faces in the picture in the upper left of the second page from the top
right of the form and ask the pressman whether it is possible to do
anything about it.
Being present also allows one to appreciate some of the
political dynamics that are always at work in any print house. The
maintenance issue described above took place at the end of the first shift.
It was only after about an hour of investigation that we could state
definitively that it was a press problem. The second-shift mechanics came
in to work on the stricken unit, but after several hours were unable to
find anything other than it did not print correctly. So we all went home.
The first-shift mechanics came in early and at length announced that the
problem would likely be solved within a couple of hours. At that point we
had fallen far behind in the schedule, and I had to fly out only two days
later, so I sat down with management to see how to proceed. At that point,
a "suggestion" was made. It seemed that , according to
management, the pressmen on the second and third shifts were very nice
people. They were model employees and fine, upstanding citizens who would
be unfailingly courteous to me if I chose to work with them.
Having made similar speeches from the other side of my
table, I replied graciously that it was very courteous of management to
offer me a choice of whom to work with, and that I was sure that the second
and third shifts would be very appreciative of those kind comments and
might not even notice the conspicuous absence of reference to their ability
to operate a printing press. And with that we decided that only the first
shift would be allowed to work on my book, even though that meant that I
would be leaving when I had only seen about a third of the pressrun.
SLEEPING AT THE PLANT.
I have done this enough that the novelty has worn off,
thank you. Similarly, if necessary I order a delivery of pizza to the
plant, but generally I prefer a restaurant with fresh seafood and a good
wine list. When the printer is competent there isn't any reason to make
such sacrifices--the purpose of my presence was to help with logistics, not
to supervise the pressrun. The job was complex, with around a thousand
different pieces, many of which involved several versions of the same
image, inviting use of the wrong version. Because of the difficulty of
scheduling a date convenient to both me and the printer, the job had
cleared editing only two days before the pressrun. That makes it very
likely that something would be missing or misidentified.
Scheduling in a run of this magnitude can be
problematic. It gets bound in two passes, so a specific section of the book
has to be completed early. Certain signatures should be printed
consecutively, if they share elements from a single series of images. Plus,
the "shift differential" spoken of above is not unique to the
printer of PP4E--it is the case at *every* printer that there is
significant differences in skill level between shifts. Usually the first
shift is the best one but certainly not always. Management of the CC/PP5E
printer gave me their opinion of the relative skill levels of the pressmen,
and, after seeing the work, I concur.
PP5E had 34 signatures, counting the cover as a
separate sig. I divided them into four categories, ranging from very
difficult with critical, subtle colors to match, to signatures consisting
largely of screen grabs. I made sure that the least important categories
were the ones being printed when I was at dinner or asleep, and that the
most important ones were routed to the press crew most capable of dealing
with any contingencies.
In the end, the net impact of my presence on the
quality of the color images of PP5E was small. What I *did* accomplish is
to notice that somebody had inadvertently placed the *uncorrected* version
of an image on the book's cover, which I didn't prepare myself. Also, the
cover has an exceedingly rich black background, because it was printed
CMYKK, with two hits of black. Whoever prepared it did not know how to trap
type in such a situation. Had I not intervened, we would probably not have
been able to read some of the small type on the back cover. Also, in one
chapter, line breaks changed enough to bump the last two lines into
alphabet heaven, in addition to making some ugly widows. So the trip was
certainly worthwhile, but not perhaps for the reason that some might think.
Of course what Dad did is not something that others can
do routinely.
I'm not your Dad, merely a calibrated moderator
<g>.
Canyon Conundrum and all five Professional Photoshop
books came out significantly better in color quality than most competitive
books, in spite of four books being produced by printers who I would
consider substandard, even forgetting that I was available during the
entire pressrun of PP5E and not for any of the previous editions . Experts
can tell that the printing of PP5E is better than that of PP4E but I don't
believe that nonexperts can.
There probably *are* some things that I did that others
can't do routinely, because I've had more pressroom experience than most.
However, the big item is not one's experience OR whether one attends the
pressrun. It is merely recognizing that the printer is your partner for
better or for worse, and that the best possible quality will be obtained
when you entice your partner to do the best job of which he is capable. It
means that you should strive to be comfortable with the printer, no matter
how bad he is, and that you should try to make him comfortable with you.
That does not mean separating with a profile that assumes he always prints
to optimal conditions, It does not mean criticizing their quality control
procedures unless you think they are going to repair them before your job
is finished. It does not mean asking them questions that they don't know
the answers to and then looking skeptical and disappointed when they don't.
These are the procedures that my friend the Unlucky Expert always employs
in order to intimidate *his* partners.
I don't remember ever going to a press check where the
presspeople were rude or where the staff was anything but courteous and
supportive--within their limits. The CSR who answers the phone may not know
enough to be of help at all. Technical people on the staff may not be able
to help with certain questions but they can with others. If you try to
manage the printer's employees the way you would like to be managed
yourself if you were in their shoes, you can get good results with or
without a press check.
Dan Margulis
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Ron Kelly"
Fri Nov 23, 2007 5:56 pm (PST)
Dan:
Most interesting inside look at the production of your
books. I thought I had stressful and complex relations with printers . . .
Now I know I'm living the simple life.
Hearing this type of detail about a printing job makes
it clear that off-set printing is much, much more complex activity than one
would suspect from looking at a few proofs.
Thanks,
Ron Kelly
___________________________________________________________________________
Moderator Warning: Civility
Posted by: Dan Margulis
Fri Nov 23, 2007 9:19 am (PST)
Members are hereby cautioned that effective right now,
contributions to the "Press Profiles" thread are subject to
scrutiny for civility. Any instances of namecalling, unprofessional
language, casting aspersions on motivations or intelligence of opponents,
or the like will result in the post being rejected at the discretion of the
moderator on duty.
Additionally, the polite request stated by me in
http:
//tech.groups.yahoo.com/group/colortheory/message/18882
is now an edict. We are here to discuss practical color
issues, not lexicography or comparative linguistics. We do not require any
language police here. Those wishing to dispute the views of others may do
so in other ways than by "correcting" the words that they choose
to use.
Accordingly, this thread has seen enough discussion of
the politically precise meaning and nuance of the verbs "to
calibrate" and "to edit." Further attempts to refine the
definition of these verbs are not welcome.
Dan Margulis
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Fri Nov 23, 2007 3:02 pm (PST)
On Nov 23, 2007, at 12:15 PM, Dan Margulis wrote:
Accordingly, this thread has seen enough discussion of
the politically precise
meaning and nuance of the verbs "to
calibrate" and "to edit." Further attempts
to refine the definition of these verbs are not
welcome.
With all due respect, there is still (apparently) much
confusion about these terms.
Speaking specifically about profile "editing"
(I made it clear as a bell that I did NOT edit the Midas profile but it was
still being referred to as a profile "edit"), I'll bet I could
poll a large group of professionals that use profile creation applications
and profile editing applications on a nearly daily basis and, to them, the
distinction between EDITING a profile vs. CREATING a profile is crystal
clear. And if I described what I did to "fix" the Midas profile,
none of them would remotely consider what I did to be an edit to that
profile but something entirely new.
Also, I really appreciated Stephen Marsh's post
regarding his technique for fixing the out-of-gamut color rendering that
was a problem with the original Midas profile. Stephen demonstrated that,
at least in this case, it wasn't necessary at all to have profile
"editing" capabilities available within Photoshop. It seemed
Photoshop already had the tools available with which to fix a
less-than-ideal rendering of out-of-gamut colors as the result of, perhaps,
an inferior profile.
I think it needs to be pointed out (again) that it
wasn't the *colorimetry* or measurement data that the profile started with
but it was with the profile application itself and it's inherent
"gamut mapping" or "rendering" capabilities. Each
profile creation application has it's own "flavor" or
"secret sauce", whatever term you want to use here, on how it
will handle out-of-gamut color issues such as we saw and this is virtually
independent of the measurement data with which you feed it. This is
probably one of my major "concerns" about using Photoshop as a
profile creation and editing application; regardless of what control you
may *think* you have when it comes to editing a profile, you are quite
likely only going to get a single "flavor" of color rendering out
of that profile no matter what hoops you jump through when attempting to
edit the profile. Even the two major professional profile applications that
I use, ProfileMaker and MonacoPROFILER, both offer different options when
it comes to gamut mapping/color rendering since this is not a
one-size-fits-all kind of thing. Would Adobe give us that kind of
flexibility if they were to essentially give away a full-featured profiling
application inside of Photoshop? Not sure. There's no doubt that they
probably have the resources to do it but I seriously doubt they would put
the necessary effort into such a "niche" tool in Photoshop.
Again, one only has to look at the "progress" they've made with
the "Custom CMYK" engine over the years to see where including
powerful profiling tools is on their priority list.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Fri Nov 23, 2007 9:36 pm (PST)
Terry Wyse wrote:
Also, I really appreciated Stephen Marsh's post
regarding his
technique for fixing the out-of-gamut color rendering
that was a
problem with the original Midas profile.
Thank you for the kind words Terry. I have used this
method a small number of times in the past with success, but only with
newsprint profiles. This is where an intermediate conversion to a different
CMYK profile can be a workable solution, before converting to the final
profile. It is not a magic bullet though and often requires some very minor
post conversion clean-up. That being said, I find that it often produces
better results than accepting the poor profile results and making post
conversion edits (or pre-conversion edits).
Stephen demonstrated that, at
least in this case, it wasn't necessary at all to have
profile
"editing" capabilities available within
Photoshop. It seemed Photoshop
already had the tools available with which to fix a
less-than-ideal
rendering of out-of-gamut colors as the result of,
perhaps, an
inferior profile. <
The method that I employed flies in the face of
conventional wisdom, I am doubtful that many would think to try it when
faced with such a situation. I don't recall seeing it mentioned in
Photoshop or colour management texts or online discussions (I try to keep
in touch but obviously miss out on so much info). The conventional wisdom
is to convert from the source RGB directly to the destination output
profile, using either RelCol+BPC or Perceptual intents. Extra conversions
are seen as 'Unnecessary' and data loss and quantization are then cited.
One does not hear how to handle transforms where the profile has no problem
with in-gamut colours but has major problems with OoG colours, which is
often the case in one image. If the entire image was OoG, then the
solutions would be far easier as the content is not mixed.
Terry, try to put yourself in the position of a
photographer, designer or prepress operator that faces a press deadline in
a day or two and is given a profile by the publisher or printer. You are no
longer a CM consultant or have access to one in this hypothetical
situation. One presumes that this profile is to be used for providing both
conversions and softproofing/proofing. When the profile is installed and
one performs evaluations, it is noted that there are potential problems
with OoG colours. It is also noted that the TIL appears rather high. One
only has Photoshop. There is no access to the hardware and or software for
working with profiles. One can't always rely on generous colour management
consultants found on industry forums to build one a new ICC file based off
the poor one in a timely fashion. Nor can one always get a good response in
time from a list or forum, let alone a new profile.
What are you to do, with your level of knowledge and
expertise? Beyond that, what is the average user to do? Remember you only
have Photoshop and a couple of days in such a setting.
As a CM consultant, it was an easy thing for you to
ingest the poor profile and generate a new profile that behaved in a
fashion as expected from experience with other similar profiles. But you
went above and beyond this! You decreased the dubiously high TIL by approx.
30%. It also appears that you adjusted how blues render, with a more
conservative magenta value for OoG blues and have slightly altered the GCR
K generation for neutrals a little heavier than the original profile.
What is the average user of Photoshop to do, that does
not have such resources? Custom CMYK appears to be shunned by many,
including some folk at Adobe - with the emphasis on standard ICC based
methods with the great addition of Adobe's BPC. Fixing a poor profile, be
it by 'editing' the profile, or 'extracting colorimetric data' from the
profile, or 'reverse engineering' the colour data from the profile in some
other way or whatever method that may possibly be used to generate a new
profile from the old would surely appear to be the best approach. My method
of converting to an intermediate CMYK space to control the rendering from
RGB to CMYK is not a panacea and one is still left with other doubtful
results from using this questionable profile for the final conversion from
the intermediate CMYK (TIL for example).
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Sat Nov 24, 2007 8:31 am (PST)
On Nov 23, 2007, at 10:59 PM, Stephen Marsh wrote:
Terry, try to put yourself in the position of a
photographer, designer
or prepress operator that faces a press deadline in a
day or two and
is given a profile by the publisher or printer. You are
no longer a CM
consultant or have access to one in this hypothetical
situation. One
presumes that this profile is to be used for providing
both
conversions and softproofing/proofing. When the profile
is installed
and one performs evaluations, it is noted that there
are potential
problems with OoG colours. It is also noted that the
TIL appears
rather high. One only has Photoshop. There is no access
to the
hardware and or software for working with profiles. One
can't always
rely on generous colour management consultants found on
industry
forums to build one a new ICC file based off the poor
one in a timely
fashion. Nor can one always get a good response in time
from a list or
forum, let alone a new profile.
What are you to do, with your level of knowledge and
expertise? Beyond
that, what is the average user to do? Remember you only
have Photoshop
and a couple of days in such a setting.
I guess I would say, with tongue partially in cheek,
that you deal with the current project but then immediately after the dust
settles you go out and get yourself a few professional profiling tools. If
you're a photographer, the cost of getting a few decent profiling tools
won't cost you more than a couple of nice lenses. A professional will get
what's necessary to get the job done right and not always rely on Photoshop
hacks, albeit creative/innovative ones.
As a CM consultant, it was an easy thing for you to
ingest the poor
profile and generate a new profile that behaved in a
fashion as
expected from experience with other similar profiles.
But you went
above and beyond this! You decreased the dubiously high
TIL by approx.
30%. It also appears that you adjusted how blues
render, with a more
conservative magenta value for OoG blues and have
slightly altered the
GCR K generation for neutrals a little heavier than the
original
profile.
I didn't jump through any special hoops. I set a total
ink limit that I knew would be more appropriate for the printing process,
something that I assume most on this list would know as well. In terms of
offset printing, there's really only about 3-4 different ink limits that
cover the entire range from newsprint to commercial sheetfed printing on
coated stock.
As far as the magenta-in-blues alteration, I had
nothing to do with it. It all came from the under-the-hood color
rendering/gamut mapping algorithms built into ProfileMaker 5.0.8.
K generation was simply a personal preference as I
really didn't even pay attention to the K gen in the original profile and
try to match it. And this is something also that can be somewhat inherent
in the profiling application. ProfileMaker for example, simply gives you
4-5 preset K gen curves and then lets you set the K start point and the K
limit (Monaco gives a bit more control when it comes to K generation).
Specific to offset printing, there's really only about 2-3 K gen
combinations that you even need to worry about. The others are there for
more extreme cases like inkjet printers and laser printers that generally
need wildly different K generation than offset printing.
What is the average user of Photoshop to do, that does
not have such
resources?
Last I checked, X-Rite will sell ProfileMaker or Monaco
PROFILER to anybody who's interested with-or-without a consultant badge. :
-)
The resources are available, just costs money that's
all, and probably not more than what somebody has paid for their initial
copy of Photoshop and the last 3-4 upgrades. Profiling applications
improve/update at a relatively glacial pace (about every 3-4 years it
seems) so it's a pretty stable investment. And with decent books available
like Real World Color Management and a couple of others, education on how
to use these tools properly is accessible to mere mortals. I know more than
a few photographers that have invested in these tools and consider them
essential to their business, almost as much as the photo gear itself.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Richard Wagner
Sat Nov 24, 2007 8:32 am (PST)
On Fri, November 23, 2007 8:59 pm, Stephen Marsh wrote:
Terry, try to put yourself in the position of a
photographer, designer
or prepress operator that faces a press deadline in a
day or two and is
given a profile by the publisher or printer.
Stephen,
There are quite a few photographers who own profiling
software and know how to use it. In fact, photographers have been at the
forefront of color management, since when things go wrong, we get blamed
for the bad result. Peter came up with an essentially identical solution to
Terry, and he's a photographer, not a color management consultant (at least
by primary description). There are also a number of good pre-press shops,
print shops, and even design firms that do quality color management,
including making their own profiles. But you're right, if someone doesn't
have the tools, or doesn't know how to use them, they're at a distinct
disadvantage. There's more to pre-press than Photoshop. It's not unlike a
car mechanic having a cart full of tools, but not having modern testing
equipment. He can fix some stuff, but he's clearly at a disadvantage
compared with a well-equipped shop. He probably won't be doing many
tune-ups on expensive sports cars and will end up doing mostly
nuts-and-bolts type fixes. Life is full of choices.
One can't always rely
on generous colour management consultants found on
industry forums to
build one a new ICC file based off the poor one in a
timely fashion. Nor
can one always get a good response in time from a list
or forum, let alone
a new profile.
Nor can the mechanic count on his friend in the other
shop down the street to always loan him testing equipment. Nor can the
photographer always borrow lighting equipment or that expensive telephoto
lens.
Remember you only have Photoshop and
a couple of days in such a setting.
Then you clearly have a problem. Bundling a mediocre
profiling package with Photoshop is not likely to solve that problem. Nor
would a good solution be to jack up the price of Photoshop to help those
few who need such capabilities. Most Photoshop users/designers aren't
making CMYK conversions nor do they need to generate profiles.
What is the average user of Photoshop to do, that does
not have such
resources?
The "average" Photoshop user won't be
involved in this at all...
Custom CMYK appears to be shunned by many, including
some folk
at Adobe - with the emphasis on standard ICC based
methods with the great
addition of Adobe's BPC. Fixing a poor profile, be it
by 'editing' the
profile, or 'extracting colorimetric data' from the
profile, or 'reverse
engineering' the colour data from the profile in some
other way or
whatever method that may possibly be used to generate a
new profile from
the old would surely appear to be the best approach.
Agreed.
My method of
converting to an intermediate CMYK space to control the
rendering from RGB
to CMYK is not a panacea and one is still left with
other doubtful results
from using this questionable profile for the final
conversion from the
intermediate CMYK (TIL for example).
I think you get great points for creativity for finding
a way to solve the problem without the ideal tools. If people want the
ability to make (or edit) profiles, there are some great software packages
out there, and I'm sure they'll be getting better. ProfileMaker is long
overdue for an upgrade. Spectrophotometers are improving and becoming less
expensive. What's the cost of a botched job? If this is your line of work,
a profiling package would be considered a good investment. In cases like
this, it clearly gives a competetive advantage. And you can charge for
re-making the profile and fixing the job - pull a couple of proofs, and let
the client see what you can do to prevent a disaster.
I'm just not very sympathetic to those who want
everything handed to them for free. There's really no entitlement here. The
software and hardware are available. If you think you might need it, buy
it. If you don't have it and you need it, think outside the box - just like
you demonstrated with this problem.
--Rich Wagner
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Sun Nov 25, 2007 4:11 am (PST)
On Fri Nov 23, 2007 8:51 am ((PST)) dremaley wrote:
Here's my question about G7 (from below). If I had a
printed sheet in front
of me how would I 'know' that it was
printed "within specification"? Under the
older SWOP standard I could read
a color bar and determine if the density,
or midtone dot gain was was correct, or within
specification.
Brunner says 80% of color deviation comes from dots
only 20% from solids.
I do agree very much with your question and conclusion.
The G7 route adds more complexity to the process and I
doubt that a lot of printers are willing to spend a lot of money on
something which does not change the behavior of their presses.
As you have pointed out: the existing tools are very
effective. Adding a colorimetric component to a guideline does not hurt
anybody, but claiming that a printer can't produce color balanced output
without it is hurting the truth.
From the GRACol7 specification information:
Realistic Expectations:
Remember that offset printing is typically much less
consistent and uniform than a typical proofing system .
Even the best press operated by the most experienced
workers under ideal conditions can vary considerably
from run to run, due to small changes in materials,
temperature, humidity, length of run, etc . The chances
of a Œperfect©ˆ press sheet from any
particular offset press
run are very small .
The goal of G7 press calibration is to adjust the plate
curves so that on an average day an average press run
will come very close to simulating the ideal G7 NPDC
and gray balance, but remember that most presses will
deviate somewhat from the target values most of the
time .
This is not my text. It is a quote, containing
"press calibration", while in fact it is about
"platesetter" calibration... I hope GRACoL wil sort this out.
The G7 "Neutral Print Density Curve" was
developed by a color consultant and not by an industry research
association, hence the terminology. It is one of three (maybe even more)
methods for installing a standardized reproduction workflow. (And not yet
ISO certified a.f.a.i.k.)
Read:
www.gracol.com/resources/Quest%20for%20Real%20standards_ManRol.pdf
----------------------------------------------------------
On Fri Nov 23, 2007 3:03 pm ((PST)), "Jim
Rich" wrote:
But if I have this wrong and you are serious and trying
to figure this out
for yourself perhaps there is a better question to ask
that is not so
pointed at hiring a consultant or selling a training
solution.
How about, what is GCR and how can it be used to make
4-color printing more
consistent? Or if you use GCR then there is less of a
chance of color
deviation. Or something along those lines.
Well, in theory, when 100% GCR would be practical
(hyper-dence-glossy-black
and perfect color to color register), NPDC would loose
it's purpose. Even
with less GCR NPDC loses it's appeal already.
The targets are based on 0% GCR...
Mileage will vary.
Yep.
Paul Foerts
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Terry Wyse"
Sun Nov 25, 2007 7:45 am (PST)
On Nov 24, 2007, at 3:13 PM, Paul Foerts wrote:
The G7 route adds more complexity to the process and I
doubt that a lot of printers are willing to spend a lot
of money on
something which does not change the behavior of their
presses.
Well, all I can say is that after
"calibrating" presses using the TVI method for several years and
then switching over to the G7 method a couple of years ago, I'd never go
back to the TVI method. The method is quite simple, certainly no more
complex than using TVI, and the IDEAlliance has nice software (IDEALink
Curve) that makes the task even easier. I suppose from the outside looking
in, the concept and procedure may appear complex but once you've gone
through the process it's not complex at all.
Furthermore, the color match you get between press and
proof, using NOT a custom press profile for proofing but just the standard
G7 characterization data set/profile, is extremely tight in my opinion,
much better than what one would achieve using the OLD SWOP specification.
Getting back to the supposed "complexity" of
the G7 method, it terms of production process control it is much LESS
complex than other methods, particular the TVI/dot gain method. Using the
TVI method, you must take no less than *9* measurements per ink zone to
properly control a press. On a typical 40" press (about 30 ink
zones/keys), this amounts to between 240-270 individual measurements. With
the G7 method this is reduced to no more than *6* readings per ink zone,
reducing the number of measurements per sheet to around 150-180. Sounds
simpler to me. I suggest you ask a pressman that has some experience
controlling their press using the G7 method vs. TVI and see which method
HE'D rather use.
Does this make TVI obsolete? Of course not. TVI can be
very useful for troubleshooting mechanical issues on press but as a
production process control method, it's a bit cumbersome and possibly
overkill.
As you have pointed out: the existing tools are very
effective.
What "existing tools" are you referring to?
With the exception of recommending that a spectro-densitometer be used
during the initial press calibration, the G7 method uses similar
"tools".
Adding a colorimetric component to a guideline does not
hurt anybody, but
claiming that a printer can't produce color balanced
output without
it is hurting the truth.
If you want to talk about real ISO
"certification", the current ISO 12647 specifications are ALL
based on colorimetry, not Status T, E or whatever densitometry. With the G7
method, colorimetry (measuring inks using L*a*b*) is really only required
during the initial calibration runs. After that, density can be used for
on-going process control and production.
This is not my text. It is a quote, containing
"press calibration",
while in fact it is about "platesetter"
calibration...
I hope GRACoL wil sort this out.
I think your splitting hairs here. Of course an offset
press cannot be DIRECTLY calibrated anymore than an inkjet printer can. We
use plate or film curves to indirectly calibrate the press. That's the way
it's always been even with the TVI method.
The G7 "Neutral Print Density Curve" was
developed by a color
consultant and not by an industry research association,
hence the
terminology. It is one of three (maybe even more) methods for
installing a
standardized reproduction workflow. (And not yet ISO
certified a.f.a.i.k.)
ISO certification will come soon but it's a long
process. SWOP was never an ISO standard AFAIK. It was a SPECIFICATION but
never a standard. At the very least, the current "G7"
specifications for GRACoL (commercial sheetfed) and SWOP (web publication)
are officially endorsed by the IDEAlliance and SWOP. In other words, SWOP
has officially stated that the current G7 SWOP *is* the official SWOP (v11
I think), not the older version based on TVI and TR-001. The older version
is still applicable as an historic reference but moving forward it will
based on the tenets of G7.
Is G7 "perfect"? No, it's not, but it's the
best thing we have right now that mostly delivers on the promise of a
"shared visual appearance" across multiple printing systems. I'm
sure as G7 gains traction, there will be minor refinements to the method
but as it stands right now it works quite well in my experience.
I'm sure GATF it is a "competent" store!
I don't think that Jim was implying they were
incompetent. My personal opinion is that GATF is feeling a bit left behind
because they weren't the primary movers and shakers of the GRACoL/SWOP/G7
effort. Industry professionals recognized that something needed to be done
here in the USA in terms of print specifications and standards and the
IDEAlliance picked up the ball and ran with it. I'm sure GATF was/is
invited to participate but there are elements within GATF that seem to be
resisting the current G7 effort.
Well, in theory, when 100% GCR would be practical
(hyper-dence-glossy-black
and perfect color to color register), NPDC would loose
it's purpose.
Even with less GCR NPDC loses it's appeal already.
The targets are based on 0% GCR...
How would "NPDC" and gray balance in general
lose it's purpose exactly? NPDC is NOT just about gray balance, it also
establishes the tone curve of the press (or printing system). With high
GCR, the neutrality component of the NPDC would be more stable but the need
for monitoring of the HC, HR and SC densities would remain the same.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Chris Murphy
Sun Nov 25, 2007 1:00 pm (PST)
On Nov 24, 2007, at 1:13 PM, Paul Foerts wrote:
The G7 route adds more complexity to the process and I
doubt that a lot of printers are willing to spend a lot
of money on
something which does not change the behavior of their
presses.
There are two aspects of G7 in my view that differ
substantially from other printing specifications: First, it compels the
press to conform to a tone reproduction curve from 0% to about 50% that is
in the spec. Other specifications only care about 100% and 50%. Nothing is
said about what 10% should look like or 20%. Small deviations in
reproduction in these areas are immediately obvious.
Second, it allows for substantial optimization with the
use of higher densities to achieve better print contrast. A major complaint
of printing specifications by many quality printers, has been that it
limits them, that they can print better than the spec. The G7 process does
allow for printers to conform where it is important that they conform: gray
balance, ink hues, highlight through middle part of mid- tones, and then
allows for transition to printing as well as they can on the substrate
being used. This is highly adaptable to other printing processes as well.
So I disagree with the assertion that it's more
complex, or that it doesn't change the behavior of the press. It can do
that if you want.
As you have pointed out: the existing tools are very
effective.
Adding a colorimetric component to a guideline does not
hurt
anybody, but claiming that a printer can't produce
color balanced output without
it is hurting the truth.
It is certainly possible to produce color balanced
output with other printing specifications, and I don't know anyone who has
said otherwise.
This is not my text. It is a quote, containing
"press calibration",
while in fact it is about "platesetter"
calibration...
I hope GRACoL wil sort this out.
The platesetter of course is also calibrated to ensure
it is consistently producing plates. But that is only part of any printing
process. The color that matters, that's being measured in the course of a
press run, are the colors actually produced on press and that too must be
maintained consistently and that is a function of press calibration.
Merely calibrating the platesetter does not inherently
mean your press is going to print all hunky dory. There's more to it than
that.
The G7 "Neutral Print Density Curve" was
developed by a color consultant and
not by an industry research association, hence the
terminology.
It is one of three (maybe even more) methods for
installing a standardized
reproduction workflow. (And not yet ISO certified
a.f.a.i.k.)
It is completely false to imply that it was developed
by a single person, that there was no pier review. There have been many
people in the print industry, both on the standards side of things, as well
as ink companies, and printing companies who have reviewed this print
specification.
Chris Murphy
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Chris Murphy
Sun Nov 25, 2007 1:00 pm (PST)
On Nov 25, 2007, at 8:23 AM, Terry Wyse wrote:
Furthermore, the color match you get between press and
proof, using
NOT a custom press profile for proofing but just the
standard G7
characterization data set/profile, is extremely tight
in my opinion,
much better than what one would achieve using the OLD
SWOP
specification.
Well, and better than what is typically the case also
without a LOT of work on the part of a European printer trying to nail a
FOGRA characterization data set, by just following ISO 12647. That spec
allows for a wider range of acceptable printing conditions that G7 would.
It is tighter in tolerance at the lighter tones, and allows for optional
customization with darker tones.
Chris Murphy
___________________________________________________________________________
Re: Press profiles, use of
\Posted by: "Terry Wyse"
Sun Nov 25, 2007 1:00 pm (PST)
On Nov 25, 2007, at 10:23 AM, Terry Wyse wrote:
Getting back to the supposed "complexity" of
the G7 method, it terms
of production process control it is much LESS complex
than other
methods, particular the TVI/dot gain method. Using the
TVI method, you
must take no less than *9* measurements per ink zone to
properly
control a press. On a typical 40" press (about 30
ink zones/keys),
this amounts to between 240-270 individual
measurements. With the G7
method this is reduced to no more than *6* readings per
ink zone,
reducing the number of measurements per sheet to around
150-180.
Sounds simpler to me. I suggest you ask a pressman that
has some
experience controlling their press using the G7 method
vs. TVI and see
which method HE'D rather use.
I should've added, this is assuming you measure the
CMYK solids at each ink zone. But with G7, you don't necessarily even need
to go *that* far. If you focus on just measuring the "HR" patch
(midtone 3- color gray) and midtone K, you can use this information to
effectively control the solids. You do this by simply measuring the HR
patch using either the "All Filters" setting or L*a*b*. This
would tell you everything you need to know about both the neutral stability
of the press run as well as the tone curve. This would reduce the total
number of measurements taken across a typical press form to less than 100
(2-3 measurements per ink key).
See, it gets even SIMPLER!
:-)
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Rick Gordon"
Sun Nov 25, 2007 4:11 am (PST)
Stephen,
Concerning TIL, what would your result be if you
converted to RGB (with BPC) and then back to Midas (with BPC) after having
converted to SWOP?
Original -> SWOP -> RGB -> Midas
___________________________________________________
RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
___________________________________________________
WWW: http://www.shelterpub.com
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Ric Cohn
Sun Nov 25, 2007 1:00 pm (PST)
On Nov 24, 2007, at 1:55 AM, Rich Wagner wrote:
I'm just not very sympathetic to those who want
everything handed
to them for free. There's really no entitlement here.
Gee, I wouldn't be very sympathetic either if I ever
met those people. Can't we leave "them" out of this. I can see
many reasons for-- and a few reasonable arguments against-- having the
ability in Photoshop to adjust things like total ink and K generation.
Whether it is reasonable or not is not something I'm qualified to
ascertain, but I don't believe asking for a solution is the same as
expecting everything to be handed to me.
Photoshop has a long history of adding features,
sometimes setting new standards for quality and functionality, sometimes
forcing others to improve their products to survive, and sometimes killing
off products because now the features were "free" in Photoshop.
For example, I was pleasantly pleased when they added a
Raw processor to Photoshop. I didn't expect it and I'm glad they've
continued to improve it. I'm not sure whether Adobe giving Camera Raw away
has a). forced other programs to improve or b). is killing off other
products which would have developed even better tools if they could charge
for them. I don't think anyone can answer questions like these with
certainty. I was also pleased some years ago when they added Extract to
Photoshop, but I was concerned that it would hinder the stand alone
products, none of which did I feel were as good as they could be, and
indeed I do believe it has by reducing the market for these products.
Unfortunately, the Photoshop team never did any further development on what
was an excellent V1 product and it's never gotten past an occasional time
saver. They also gave us a free tool for fixing lens distortion. I had
already paid for a stand alone product which was even better, but they're
out of business because they couldn't develop anything compelling enough to
compete with free.
What are we to take from these lessons? That Photoshop
shouldn't change? Ridiculous! That anyone can predict what are the best
features to add to Photoshop? I don't think so. I think the only question
from Adobe's point of view would be whether enough more programs would be
sold (or customer stealing competition suppressed) by spending the money
and resources to develop it. IMHO it would a). be worth it to update Custom
CMYK and b). in today's world I think that implies the ability to work with
ICC profiles. It doesn't matter if I'm right or wrong, I believe I have the
right to express my opinion without being insulted.
Ric Cohn
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Terry Wyse"
Sun Nov 25, 2007 1:00 pm (PST)
If you use BPC in each conversion, the TIL of a 0,0,0
RGB will come out using the max TIL of each CMYK profile. I just tried it
using your conversion path (I replaced the "Midas" profile with
the GRACoL2006_Coated1 profile) and the TIL come out the max TIL of each
respective profile.
The kicker is that the SWOPv2 Dmax/TIL of c75m68y67k90
goes right back to r0g0b0 when you convert back to RGB from CMYK.
Naturally, since this is back to r0g0b0, the next conversion to CMYK will
use the Dmax/TIL of THAT profile.
Perhaps this is what you're looking to do: If you
convert from CMYK back to RGB with BPC *off*, you'll get something less
than r0g0b0 (r40g40b40 in this example)) which in the subsequent conversion
to CMYK (BPC *on* this time) will convert to something less than the max
TIL (about 290% in my case using the GRACoL profile).
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Henry Davis
Mon Nov 26, 2007 2:41 pm (PST)
On Nov 23, 2007, at 3:54 AM, Chris Murphy wrote:
So a press is controllable? And yet it cannot be
calibrated?
A press is controllable. Why do you continually
question what I didn't say?
Where are you talking about color management? You've
stated, as fact,
that presses can't be calibrated. That is easily proven
false.
G7 and other "standards" have been mentioned,
as well as profiles that are suitable for them. This doesn't imply color
management?
There is such a thing in instrument flying called
non-precision
approaches, and precision approaches. The primary
differentiating
factor is glideslope, rather than stepped down descent
based on
distance from a fix, a precision approach expect you to
be in a
particular place in 3D space.
The flying analogy applies:
A similar kind of distinction is what I would expect
would be acceptable for printing. A non-precision approach is a description
that is more appropriate for that type of approach. Non-precision
approaches have been and are still an acceptably safe practice. If you were
to ask the passengers which they would prefer, a precision or non-precision
approach, what do you think they will choose? Print buyers and designers
are in the same state of confusion with the words calibrate and standards.
If G7 becomes what is generally accepted as a
"calibrated" press, then the assumption that the less informed
will make is that if it isn't G7, it isn't calibrated.
I think this sums it up for me. When people see these
words coupled together, it will be hard to convince them that they aren't
one in the same. That they actually just describe another range of
tolerances will be lost in the process.
Henry Davis
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Mon Nov 26, 2007 2:41 pm (PST)
On Sun Nov 25, 2007 7:45 am ((PST)) "Terry
Wyse" wrote:
I think your splitting hairs here. Of course an offset
press cannot be
DIRECTLY calibrated anymore than an inkjet printer can.
We use plate
or film curves to indirectly calibrate the press.
That's the way it's
always been even with the TVI method.
Most people would agree: there is a BIG difference
between a press and a platesetter...
Well, a stable inkjetprinter can be calibrated. A
stable image- or platesetter can be calibrated. A press cannot!
"Make sure press is mechanically sound" is #1
in the "press calibration steps" by "GRACoL. How gets this
"calibrated"?
Is G7 "perfect"? No, it's not, but it's the
best thing we have right
now that mostly delivers on the promise of a
"shared visual
appearance" across multiple printing systems. I'm
sure as G7 gains
traction, there will be minor refinements to the method
but as it
stands right now it works quite well in my experience.
I've never said it is "bad".
I wrote: The G7 route adds more complexity to the
process and I doubt that a lot of printers are willing to spend a lot of
money on something which does not change the behavior of their presses.
I add:
When printers have several presses and need different
"compensation curves" for their platesetters... the plates are no
longer interchangeable between presses. Is this making things simpler for
the printers?
Changing plate values has "always" been a
last resort for the printer when he could not match a proof. Here it is
re-introduced as "press calibration". An emergency exit gets
qualified as main entrance.
Paul Foerts
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "Richard Wagner”
Mon Nov 26, 2007 2:41 pm (PST)
On Nov 24, 2007, at 1:13 PM, Paul Foerts wrote:
The G7 route adds more complexity to the process and I
doubt that a lot of printers are willing to spend a lot
of money on
something which does not change the behavior of their
presses.
I don't think it's "more complex," nor is it
"more expensive." Your doubt that printers are going to accept G7
is sort of amusing, given the fact that GRACoL and SWOP have both already
embraced G7 and accepted it as their new standard. Yup, the old
"SWOP" is obsolete, and new SWOP proofs, profiles, etc. are
already based on G7. The new SWOP specs were just published last May (you
can download them for free here: http:
//www.swop.org/specification/SWOP2007Specserrata.pdf or http:
//tinyurl.com/2wlz9j). Those interested may download the new SWOP ICC
Profiles, Characterization Data Sets, G7 "How To", and an
Introduction to SWOP here: (http://www.swop.org/resources/ downloads.asp or
http://tinyurl.com/37k56s).
As far as printers not being willing to "spend a
lot of money" on G7, the list of major players that run SWOP and
dictate its direction is fairly impressive:
http://www.swop.org/about/organization.asp
The G7 "Neutral Print Density Curve" was
developed by a color
consultant and not by an industry research association,
hence the terminology.
It is one of three (maybe even more) methods for
installing a standardized
reproduction workflow. (And not yet ISO certified
a.f.a.i.k.)
A few clarifications are in order. Don Hutchison was
certainly involved in the development of G7 as the chairman of the GRACoL
committee, but he didn't do it single-handedly. The PowerPoint presentation
by Don that you cite is from 2004 or so - a lot has happened since then. G7
was actually developed by the IDEAlliance - and GRACoL and SWOP are both
specifications of the IDEAlliance, so let's not give Don more credit than
is due. While the entire G7 process is not an ISO certification, the
process is closely tied to ISO standards:
To quote: (http://www.gracol.org/resources/quiz.asp)
G7TM is a the new IDEAlliance publication that outlines
methods to calibrate proofing systems and presses based on principles of
digital imaging, spectrophotometry, and computer-to-plate (CtP)
technologies. G7 is currently being applied to many types of printing
including commercial and publication printing, newsprint and even flexo.
This publication utilizes the existing ISO 12647 Standards as the basis for
good printing. G7 specifies printing with inks defined by ISO 2846-1 so
that the dry solids measure as close as possible to the ISO CIELab values
for seven colors - the four primary colors and three 2- color overprints
specified in ISO 12647. Because our goal is to simplify calibration to help
the printers reliably achieve a close "visual match" from proof
to press, G7 breaks from tradition by focusing on colorimetric data for
gray balance in the mid-tones rather than on densitometric aims, i.e. dot
gain, for each color. G7 is named for its gray scale calibration technique
and the 7 ISO ink colors it requires. G7 is a trademark of IDEAlliance.
Although G7 was developed by the efforts of the GRACoL Committee, it should
not be confused with GRACoL or with GRACoL 7.
You can download the new GRACoL spec for sheetfed
printing, as well as the new color bars here (again, free):
http://www.gracol.org/resources/
The new SWOP / GRACoL profiles have been released,
print and pre-press shops are using them, and the industry is changing,
with a convergence of both SWOP and GRACoL on G7. There are already 123
" G7 Master Printer" certified shops in the US, even though the
certification process has barely started (masterprinter.idealliance.org).
There are also 6 "Master Printer" G7 certified shops in China!
(http://tinyurl.com/3a5748)
The current direction of the printing / graphics arts
industry is to make everyone involved in the process a
"calibrationist," with a goal of "printing to the
numbers" with images that begin the publication journey on calibrated
monitors and end on calibrated presses. (SWOP-certified monitor proofing is
just around the corner - certification just started, and monitor proofing
certification is "to the numbers.") Not every printer or prepress
shop or designer will make the switch - just like many are currently
clueless about the old SWOP. But the big players and shops are already
committed and this is not going to fade away. Even PIA/GATF is joining the
party. Their annual Color Management Conference next month (http://
www.colormanagementconference.com/) will have a "G7 Day" that is
devoted strictly to G7 and the new standards and how they will affect the
printing / graphic arts industries. And print shops are already advertising
their "Master Printer" G7 certification for competitive
advantage.
http://www.corp-image.com/learn_color.html
People in this industry have a choice - they can stay
up-to-date with current technology, standards, and innovation, or they can
try to hang onto the technology and techniques of the past and do things
the way they always have. Life is always full of choices.
--Rich Wagner
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Chris Murphy
Mon Nov 26, 2007 11:13 pm (PST)
On Nov 26, 2007, at 2:33 PM, Paul Foerts wrote:
Well, a stable inkjetprinter can be calibrated. A
stable image- or
platesetter can be calibrated. A press cannot!
Yet you fail to take into account a number of responses
to this assertion regarding tolerances. An inkjet clearly has a different
level of repeatability than a press. A platesetter has a level of tolerance
tighter than that of a press. That does not inherently disqualify a press
from being calibrated.
I add:
When printers have several presses and need different
"compensation
curves" for their platesetters... the plates are
no longer interchangeable
between presses. Is this making things simpler for the
printers?
Yes, in that they now at least have an option to print
consistently between presses whereas previously they were screwed if they
weren't using transfer curves.
Changing plate values has "always" been a
last resort for the
printer when he could not match a proof. Here it is
re-introduced as "press
calibration". An emergency exit gets qualified as
main entrance.
Hyperbole. A better understanding has been reached, and
the paradigm of which you speak is passing. I think that's a good thing
because press process control is better understood, better documented, a
better implemented instead of ignoring a tool that's been there for while.
The primary reason why it has been a last resort and is now common place is
because film is dead. People don't transport a set of film around anymore,
nor do they do this with plates. They do it with digital files. Big
difference.
Chris Murphy
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Mon Nov 26, 2007 2:41 pm (PST)
Rick Gordon wrote:
Stephen,
Concerning TIL, what would your result be if you
converted to RGB
(with BPC) and then back to Midas (with BPC) after
having converted to
SWOP?
Original -> SWOP -> RGB -> Midas
Firstly, thank you for the response Rick, and Terry for
fielding a reply while I was busy at work.
As both 'theory' suggested and 'applied theory' proved,
the RGB step does not help for the TIL when using BPC and may tend to add
1% or 2% more scum dots to 'pure' hues (needless extra RGB conversion, on
top of another "needless" CMYK conversion that proves to be very
needed in this case!).
You *are* onto something Rick, just not with the BPC
on, but with the BPC _OFF_ as Terry correctly pointed out. To Recap, the
Midas profile delivers approx. 343%, 88c 80m 84y 91k TAC/TIC/TIL (whatever
term you like).
My original method was:
A98 RGB -> SWOP v2 CMYK (RelCol+BPC) -> Midas
CMYK (RelCol+BPC)
Terry mentioned a modification to your suggestion of:
A98 RGB -> SWOP v2 CMYK (RelCol+BPC) -> ?RGB
(RelCol, BPC OFF!) -> Midas CMYK (RelCol+BPC)
In my tests with BPC off, I used A98 again after the
SWOP step. The final result when converting to the Midas profile is 290%
(-53%). Sounds good, but...
A simpler approach would be to modify my original steps
to read:
A98 RGB -> SWOP v2 CMYK (RelCol+BPC) -> Midas
CMYK (RelCol, BPC OFF!)
This results in a TIL of 317%. Sounds good again, right
(-26%)?
But what happens when we examine the ink build for the
deepest shadow (0r0g0b)?
290% method = 85c 73m 76y 56k. Yes, 56k! Far too weak
in the black channel. 317% method = 87c 76m 80y 74k. Better black, but it
could still use a boost and the CMY to come down a little to compensate
(going for a target TIL of 320-330%). Goes to show just how good that
'smart'CMM BPC feature of Adobe's is. What a shame that they did not
licence Imation's 'smarter' CFM, as Adobe has a far greater market presence
with Photoshop.
I personally think the 317%-74k value is better to work
from than the 290%-56k value (tested with very low key near neutral content
with detail).
As the TIL was not originally an issue of complaint I
did not address this aspect when originally commenting (only saturated
colours were noted as being a problem). Rick, I am glad that you chose to
comment on my latter reply on TIL, otherwise this BPC on/off topic may not
have come up in the thread. And Terry, thank you for the BPC off
suggestion.
Congratulations for keeping the innovative Photoshop
hacks going! Long live the hack!
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: Stephen Marsh
Mon Nov 26, 2007 2:41 pm (PST)
Terry Wyse wrote:
A professional will get what's necessary to get the job
done right
and not always rely on Photoshop hacks, albeit
creative/innovative ones.
Fair enough Terry, I could agree on general principle,
but knowing how things play out in various studios and print shops I will
likely retire from the trade before all and sundry have monitor
hardware/software - let alone the hardware and software for making press or
other profiles. So, it looks like I had best keep coming up with more
Photoshop hacks!
I didn't jump through any special hoops. [snipped]
Thanks Terry for expanding on the differences between
the profile that you generated from the doubtful source profile.
Thanks for taking the time for the long response Terry,
I have no time/energy for a 'great debate' so I will not be making any
controversial remarks (much to the disappointment of the devil on my
shoulder).
Thank you again for the exchange.
Sincerely,
Stephen Marsh.
___________________________________________________________________________
Re: Printer profile bad?
Posted by: "Richard Wagner"
Mon Nov 26, 2007 2:41 pm (PST)
On Nov 25, 2007, at 1:26 PM, Ric Cohn wrote:
I can see many reasons
for-- and a few reasonable arguments against-- having
the ability in
Photoshop to adjust things like total ink and K
generation. Whether
it is reasonable or not is not something I'm qualified
to ascertain,
but I don't believe asking for a solution is the same
as expecting
everything to be handed to me.
Fine, but that's not what was requested. The features
that were requested were essentially a full-blown profiling application
like MonacoPROFILER or X-Rite's ProfileMaker. But, hey, Adobe has a
standardized mechanism for feature requests. If you (and others) make your
requests through the proper channels, like their feature request form, you
might just end up with what you want in CS4. Or you might not. Either way,
it's not my call. I just don't think it's likely to happen.
http://www.adobe.com/cfusion/mmform/index.cfm?name=
wishform or http://tinyurl.com/msode
--Rich Wagner
___________________________________________________________________________
Press profiles, use of
Posted by: "Paul Foerts"
Tue Nov 27, 2007 8:05 am (PST)
On Mon Nov 26, 2007 2:41 pm ((PST)) "Richard
Wagner" wrote:
Even PIA/GATF is joining the party.
Their annual Color Management Conference next month
(http://
www.colormanagementconference.com/) will have a
"G7 Day" that is
devoted strictly to G7 and the new standards and how
they will affect
the printing / graphic arts industries. And print shops
are already
advertising their "Master Printer" G7
certification for competitive
advantage.
I hope PIA/GATF will at least have the courage to point
out to their member printers what this G7 is all about. (Announced Panel:
Confessions of G7 Implementations) I would welcome they put the constraints
next to the merits of this hyped tool/methodology. I hope they will comment
on criticisms heared in the 2007 TAGA conference (most comments seemed
opposed to it).
Yes I know, the train is on track. It is however never
to late to inform the voyagers about the direction this train is going.
Printers don't spend much time on reading the fine
print.
Printers do attend conferences for getting opinions,
quick answers and good tutorials, not for worshipping marketing gurus or
the "Cookout". (Well this may not be completely true for some :
-))
People in this industry have a choice...
Yes, they are free to reject or adopt "new"
standards or terminologies.
So I'm also free to express my own opinion.
Paul Foerts
PS: On Mon Nov 26, 2007 11:13 pm ((PST)) "Chris
Murphy" wrote:
Hyperbole. A better understanding has been reached, and
the paradigm
of which you speak is passing.
Amen.
___________________________________________________________________________
Re: Press profiles, use of
Posted by: "John Romano"
Tue Nov 27, 2007 8:06 am (PST)
Paul
I wouldn©ˆt say it adds complexity, its just
different and if the printers aren©ˆt going to Spend the money to
help set their presses to a good standard then they will loose Jobs.
Yes Printers can have more than one press..... But you
can make them all similar so that The same curve set works for all or use
individual curves for each. Not the end of the world either way.
Changing plate curves are still a last resort, nothing
says you still cant change your curves.
Sorry I don©ˆt get any of your points, they
are not in the real world.
John R
___________________________________________________________________________
Re: Press profiles, use of
Posted by: remaleydan
Tue Nov 27, 2007 10:58 am (PST)
Hi Jim, no tricks here,. Just asking how and what.
Terry explained it a little for me. Yeah, I©ˆm a process control
geek, you know úwant to measure stuff ú the right stuff! I
believe, and understand, printing to gray balance, done it all my life.
I©ˆm looking for the process control measurement and the standard
deviation of those measurements. I©ˆm sure that once the curves
are set and Lab©ˆs are hit - it©ˆs perfect!
I©ˆm worried about next week, when Œsomething©ˆ
changes. I©ˆm a little concerned that the measurement of gray
only for run control, without tolerances for TVI and density, might be
trouble. Just looking for the ©¯specs.©˜ I believe ISO
has the same concerns. . .Brunner says 80% of the problem is TVI ú
maybe we need Lab of the 50% tints? Just asking. . .
Dan Remaley
Sr. Tech. Consultant Process Control
412.591814
___________________________________________________________________________
Re: Press profiles, use of
Posted by: Lee Clawson
Tue Nov 27, 2007 11:03 pm (PST)
Dan,
Do you want to measure TVI (tone value increase) or
just know if its consistent ??
Also, is TVI dot gain or some variation of the effect
??
Lee Clawson
2/\V/\7 Studio
____________________________________________________________________________
Thanks Peter and Terry,
Posted by: "Steve Peters"
Sun Dec 23, 2007 8:53 am (PST)
I just wanted to thank everyone, especially Peter and
Terry for taking the time to try and help fix a bad printer profile. I
finished the job a while ago actually and I did first try and use the new
profiles you guys sent, but in the end I ended up using the SWOP3v2 profile
I got from SWOP.org. I sent them proofs from my Epson 4800 with the
Colorburst rip and the came out very close.
Thanks everyone,
Steve Peters
II. Are These Dot Gain Numbers for Real?
CMYK numbers
Posted by: "John Denniston"
Thu Jan 10, 2008 11:18 am (PST)
A friend of mine is preparing some photographs of
paintings for a glossy art magazine and was requested to provide CMYK with
the following dot gain 73-71-71-77. He was concerned with the high number
for black and I could think of no explanation why it would be so much
higher than cyan.
Can anyone here explain?
Regards,
John Denniston
www.dirtbikephoto.com
www.johndenniston.ca
www.dennistonphoto.com (Blog)
___________________________________________________________________________
Re: CMYK numbers
Posted by: "Jim Donovan"
Thu Jan 10, 2008 3:01 pm (PST)
Hi John, There is some confusion here. My guess is
73-71-71-77 are cmyk values,not dot gain values,two different things.Have
you or your friend ever made files or seps for cmyk offset printing? I ask
because the question dose not make any sense and good shadow detail in
offset printing is dependent on the black plate and unless you are looking
for a non-neutral casted shadow the black value will always be higher than
the cyan in the deep shadows with detail. You may want to see if the
magazine can convert to cmyk for you if you are unsure about making cmyk
offset files. Jim Donovan
___________________________________________________________________________
Re: CMYK numbers
Posted by: "Alessandro Bernardi"
Thu Jan 10, 2008 4:09 pm (PST)
"Jim Donovan" wrote:
Hi John, There is some confusion here. My guess is
73-71-71-77 are cmyk
values,not dot gain values,two different things.
I strongly agree with you Jim, these values seems to me
to be the maximum values for the shadows even if the cyan should be a
little bit higher to be neutral. In this case the total will be 292 that is
a suitable value of the Total Ink Limit for an art glossy magazine. I have
never seen a dot gain about 70%, it's impossible, the 50% of any ink would
be higher than 100%... impossible.
You may want to see if the magazine can convert to
cmyk for you if you are unsure about making cmyk offset
files.
I think this is a good suggestion.
John, making a cmyk offset file with the wrong settings
can be a drama for the final result and if the beginning is so confused I
think that giving an RGB file to the magazine WITH its own Color Profile
embedded could be the best choice.
Or better, before giving the files you can convert them
in LAB that don't suffer of any color profile problem.
They'll convert the files in cmyk with the right
settings for each
subject.
Alessandro Bernardi
___________________________________________________________________________
Re: CMYK numbers
Posted by: Henry Davis
Thu Jan 10, 2008 4:51 pm (PST)
On Jan 10, 2008, at 2:04 PM, John Denniston wrote:
A friend of mine is preparing some photographs of
paintings for a
glossy art magazine and was requested to provide CMYK
with the following
dot gain 73-71-71-77. He was concerned with the high
number for black and I
could think of no explanation why it would be so much
higher than cyan.
Couldn't it just be that this is the value expected for
50 percent?
Expressed as gain it would be 23 / 21 / 21/ 27.
Henry Davis
___________________________________________________________________________
Re: CMYK numbers
Posted by: "Jim Bean"
Thu Jan 10, 2008 4:51 pm (PST)
I think the initial post simply used the term 'dot
gain' in error.. a few more points of K might be something to insure a
decent black and doesn't seem to be out of line to me...
however, thinking the printer/publisher is going to 'do
the right thing' and convert your rgb or lab to the 'correct' cmyk for
"each subject using their profiles" is a huge leap of faith.. 2-3
months ago the cover image of a professional photography magazine likely
used that same mindset ... the cover image on supposedly the magazine for
pros was a dog. The lady's face was hot magenta without much cyan
apparent... I bet someone also thought that 'using the printer's profile'
would be a snap...certainly nothing wrong with taking a shot at the
conversion... but someone with a bit common sense needs to look at 'those
numbers' and see if an obvious error may have occurred.
jim bean
___________________________________________________________________________
.
Re: CMYK numbers
Posted by: J Walton
Thu Jan 10, 2008 4:51 pm (PST)
On Jan 10, 2008 3:30 PM, Alessandro Bernardi wrote:
I strongly agree with you Jim, these values seems to me
to be the
maximum values for the shadows even if the cyan should
be a little bit
higher to be neutral.
In this case the total will be 292 that is a suitable
value of the
Total Ink Limit for an art glossy magazine. I have
never seen a dot
gain about 70%, it's impossible, the 50% of any ink
would be higher
than 100%... impossible.
I was actually assuming something different. I was
thinking that 73-71-71-77 is what 50/50/50/50 would turn into. In other
words the dot gain would be 23/21/21/27 which seems OK to me.
You may want to see if the magazine can convert to
cmyk for you if you are unsure about making cmyk offset
files.
I think this is a good suggestion.
Yeah, I'd say either have them give clearer info (which
they may have and we just didn't get it) or supply a profile. If they can't
do that then give them LAB and let them do it.
--
J Walton
___________________________________________________________________________
Re: CMYK numbers
Posted by: "John Denniston"
Thu Jan 10, 2008 6:39 pm (PST)
My news years resolution is not to send any message to
any list serv without reading it first with my glasses on.
Numbers should have been 23-21-21-27
Sorry for the confusion.
Regards,
John Denniston
www.dirtbikephoto.com
www.johndenniston.ca
www.dennistonphoto.com (Blog)
___________________________________________________________________________
.
CMYK numbers
Posted by: "Paul Foerts"
Fri Jan 11, 2008 7:11 am (PST)
John,
Is this about a filmsetter or a platesetter workflow?
When using the film (or conventional) workflow, the
dots on the film are the reference. Hence "dotgain".
When a CTP workflow is used, the dots on the plate will
be the reference. In this case the terminology "tone value
increase" (TVI) should be used.
Why?
The conventional workflow adds extra dotgain to the
process (about 3% at 50% film value).
When positive working plates are used, a loss of the
same amount can be measured on the plate.
In today's CTP workflows, plates are made linear: an
input value of 50% will result in a tone value of 50% on the plate.
(Proprietary values are possible)
So, what is the reference value for your numbers? Is it
50 % film value? Is it 50% plate value?
In your case, I would not mind. It is up to the printer
to help your friend with his file preparation. A testfile may help.
Paul Foerts
___________________________________________________________________________
Re: CMYK numbers
Posted by: "PIA GATF"
Fri Jan 11, 2008 7:11 am (PST)
That could be it Henry.
Under the Œold? SWOP standard - the relationship
was (and no one knew it) that at press, for gray balance, the % dot values
Black (+2)
Magenta (0)
Cyan (0)
Yellow (?2)
In other words K22 M20 C20 Y18 was the Œstandard?
but- Black+2% more Yellow
-2% less, Mag/Cyan the same=
The variance could be +/- 3% or
K25 M23 C23 Y21 (high- but gray)
Or
K19 M17 C17 Y15 (low- but gray)
I have a reference piece that shows this relationship,
send me an E-mail and I?ll forward a pdf - or send me your mailing address
and I?ll send hard copy.
Dan Remaley, PIA/GATF
Sr. Tech. Consultant Process Control
412.259.1814
___________________________________________________________________________
Re: CMYK numbers
Posted by: Dan Margulis
Sat Jan 12, 2008 6:17 am (PST)
Other things being equal, dot gain is greater in a
darker ink, so we expect in principle that the dot gain from highest to
lowest is KMCY. In the real world, often M=C and little attention is paid
to Y because it is such a light ink that it doesn't make a lot of
difference if we are slightly off with it. So if you know nothing at all
about the printing conditions, a good guess is that C=M=Y and black is 2-4
points higher.
The numbers you were given have the ring of truth to
them, because they're close enough to the expected values that they could
certainly be correct, yet they wouldn't be found in any book, so the
printer isn't just blowing smoke by reciting some standard that he's heard
about elsewhere. Somebody at some time actually thought that these were the
correct values; whether they are currently the correct ones is an open
question.
If this is indeed a fine art magazine, a likely
explanation for these numbers is that, being a fine art magazine, they
print on nice white stock and the management found that the type looked
gray. I'd guess that the design of the magazine uses Caledonia or
Baskerville or some other serifed face with thin lines, and management may
have decided that the least evil approach is to print with more black ink
than others use and to hell with SWOP or any other standard, since many of
their advertisers are preparing their work for them custom anyhow.
So I would try to get a copy of the magazine and see if
there is evidence that the above surmise is correct. If so, then I'd give
these numbers the benefit of the doubt. If not, I'd suspect that they're
dated and would use them as a loose guideline only.
Dan Margulis
___________________________________________________________________________
Re: CMYK numbers
Posted by: Terry Wyse
Sat Jan 12, 2008 11:01 am (PST)
On Jan 12, 2008, at 9:15 AM, Dan Margulis wrote:
Other things being equal, dot gain is greater in a
darker ink, so we
expect in principle that
the dot gain from highest to lowest is KMCY.
But of course they are not, even under good printing
conditions.
In the real world, often M=C and little
attention is paid to Y because it is such a light ink
that it
doesn't make a lot of difference
if we are slightly off with it. So if you know nothing
at all about
the printing conditions, a
good guess is that C=M=Y and black is 2-4 points
higher.
Based on my experience calibrating presses (OK, not
CALIBRATING but creating "dot gain compensation curves"), there
is no rhyme or reason to what ink may show the most dot gain. In quite a
number of cases, while K is generally the highest, the Yellow and Magenta
can come in a close second to Black while the Cyan tends to run with the
LOWEST dot gain of the other three inks with the native gray balance being
just a bit on the "warm" side before either "G7"
calibration or dot gain compensation is performed. This has happened to me
too many times with too many different ink vendors and press combinations
to simply be a coincidence.
In regards to the original post and the dot gain
values, they *sound* reasonable but without knowing what press stock is
being used, it's a bit of a crap shoot. They are a bit high (OK, a LOT
high) if we're talking linear CTP on coated paper but they are probably a
bit low if we're talking uncoated papers. Also, before running off and
making a profile using these values (please tell me you're not going to use
"Custom CMYK" to do this? Eek!), you need to know what the
expected L*a*b* values of the solid primaries and secondaries should be and
what the recommended total ink limit should be. These last two things are
at least as important as what the expected dot gain or "TVI"
values should be. My advice would be to do a bit of research and see if
there's a "standard" profile out there that will do the job.
Since the quoted TVI values are a bit higher than SWOP, you might start
looking at the various ISO standard profiles and see if there's one that
fits the bill. The ISO/Fogra profiles are organized by the type of press
stock they are designed for so perhaps you can find something there.
Good luck!
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: CMYK numbers
Posted by: Jim Rich
Sat Jan 12, 2008 1:27 pm (PST)
Terry, Dan, et al,
It sure would be nice if all things were equal in
relationship to color printing.
But...unfortunately when it comes to color printing,
gray balance and dot gain there is no easy rules-of-thumb without using a
systems approach with the right tactics and tools.
I agree with Terry there seems to be no real reasoning
about TVI (DotGain) and what it measures on the final printing without
having a measurable target.
For example, recently, I calibrated a dot proofer and a
4 color press, (targeting ISO 12647 using the G7 method). The Yellow dot
gain when we stared was 25% (on both) and the other colors (CMK) were in
the teens. And looking back through my work notes I see this as a trend
based on the last few press I set up. way. This too much yellow dot gain.
But that does not mean it is always a common press behavior to look for.
IMHO, a person can guess at this stuff all day long,
however, to know for sure about gray balance and dot gain on a final
printed sheet, you need a known target printed and you have to measure it.
My observation and experience is that if you don't use that approach then
you are just guessing.
Jim Rich
___________________________________________________________________________
.
Re: CMYK numbers
Posted by: Lee Clawson
Sat Jan 12, 2008 10:06 pm (PST)
on 1/12/08 11:26 AM, Terence Wyse wrote:
...[snip]...you need to know what the expected L*a*b*
values of the solid
primaries and secondaries should be and what the
recommended total ink limit
should be. These last two things are at least as
important as what the
expected dot gain or "TVI" values should be.
...and I'll strongly second that.......
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
.
Re: CMYK numbers
Posted by: "Todd Shirley"
Tue Jan 15, 2008 4:51 am (PST)
Hi John
Terry, Dan and Jim all had excellent things to say
about 23-21-21-27 dot gain, but I think the most important thing is that
whoever requested these images didn't give your friend nearly enough
information! As has been said, these numbers are perfectly meaningless
without the full context: What is the total ink limit? What kind of stock?
What is the printing process?
Your friend needs to go back to the magazine and ask
for an official spec sheet on how files are to be submitted. I've dealt
with hundreds of publications, and everybody has SOMETHING, sometimes even
a website! I've never seen a spec sheet that just lists dot gains and
nothing else - there has got to more to it, especially if they want a
contract proof that they are going to (attempt) to match.
-Todd Shirley
___________________________________________________________________________
Re: CMYK numbers
Posted by: Dan Margulis
Wed Jan 16, 2008 4:56 am (PST)
Terry writes,
But of course they are not, even under good printing
conditions.
The SWOP standard, unless they've changed it recently,
is K>C=M>Y. If C and M are different the chances are that, as you
note below, the cyan is less. All of the shops I've been employed by were
K>M>C>Y, but maybe they had better than average ideas of process
control. You and Jim Rich are both correct that other results often occur.
Nevertheless, if you have to bet on what result you will find at an unknown
printer, I would reiterate that K>M>C>Y may not be the case in the
majority of print shops, but it is more likely than any other single
combination.
Based on my experience calibrating presses (OK, not
CALIBRATING but
creating "dot gain compensation curves"),
there is no rhyme or reason
to what ink may show the most dot gain. In quite a
number of cases,
while K is generally the highest...
If black is generally the highest then there *is* a
rhyme or reason to what ink may show the most dot gain.
In regards to the original post and the dot gain
values, they *sound*
reasonable but without knowing what press stock is
being used, it's a
bit of a crap shoot.
Yes, but such crapshoots are nothing out of the
ordinary in the real world.
Also, before running off and making a
profile using these values (please tell me you're not
going to use
"Custom CMYK" to do this? Eek!),
I'm not a great expert on CS3; did they slip a
satisfactory substitute for Custom CMYK in when I wasn't looking? I was
told that there wasn't one in late beta, but certainly it would have been
easy enough to add it at the last minute. The only prerequisites are really
trivial, we merely have to be able to enter the new values and generate a
new profile in a minute or less, and that it be editable in case these
proposed dot gains prove not to be quite correct, or in a case like this
where we certainly would want to use a UCR-type separation.
Back in CS2, for this necessary exercise, which
requires no great Photoshop or calibration expertise, the suggestion was
made that we should hire a color management consultant to go track down
this printer and create a new profile that might or might not be better
than the one generated in less than a minute, and that we then spend $2,500
for a software package so that we can edit the result. It is not obvious
how those advocating this were able to maintain a straight face, but some
did.
you need to know what the expected
L*a*b* values of the solid primaries and secondaries
should be and
what the recommended total ink limit should be.
Always dangerous to use phrases like "*you* need
to know" when the meaning is "*I* need to know." I did not
notice in the OP any mention of this information, and strongly suspect it
is not available. If *you* need to know it before proceeding, then, fine,
it probably means that you turn down this job. Me, I'd love to know more,
too, but already I know more than is available from the typical printer who
claims to be "SWOP".
My advice would be to do a bit of research and see
if there's a "standard" profile out there
that will do the job. Since
the quoted TVI values are a bit higher than SWOP, you
might start
looking at the various ISO standard profiles and see if
there's one
that fits the bill. The ISO/Fogra profiles are
organized by the type
of press stock they are designed for so perhaps you can
find something
there.
While doubtless these profiles have their merits, they
will not reflect the aberrant dot gain that we suspect may be in play here.
They will certainly not be of the UCR variety that experienced people would
demand when we suspect, but do not know, that something unusual is going on
with respect to black. It would certainly be nice if we could consider
using these existing profiles as a base, but unfortunately they are
rendered useless to the OP by the spiteful refusal of the Photoshop
engineering team to do anything for the CMYK community that it considers to
be its enemy.
One would hope that at some point someone in Adobe
upper management would develop enough spine to simply stand up to the
Photoshop engineers and *order* them to code in the rudimentary profile
editing capability that * should* have been done in 1998 and that would
make the lives of the OP, and many others, so much easier in common cases
like this one.
Dan Margulis
___________________________________________________________________________
Re: CMYK numbers
Posted by: "John Denniston"
Wed Jan 16, 2008 4:56 am (PST)
Hi Todd,
My friend has all of the other necessary info but it's
all standard specs and what he or I would expect from a glossy magazine. I
found the dot gain for black unusual, however, and that's why I asked about
it. Dan's explanation about the text makes sense. As it turned out, after a
few consultations with the designer, they changed their mind and have
requested AdobeRGB files with proofs and will make the separations
themselves.
Regards, John
John Denniston
www.dirtbikephoto.com
www.johndenniston.ca
www.dennistonphoto.com (Blog)
___________________________________________________________________________
.
Re: CMYK numbers
Posted by: remaleydan
Wed Jan 16, 2008 8:34 pm (PST)
Just a couple of points - PIRA the consulting,
training, and research group in Europe researched the color combinations of
KCMY and KMCY. The results were that the sequence of KCMY is preferred -
the reason is that when Mag and Yel print together the "reds" are
better than when the Cyan is between Mag and Yelo. In this sequence the
greens suffer a bit. When the sequence is changed to KMCY the greens are
'better' but the "reds" are terrible, and since we'll accept
larger differences in greens, than in reds, the best sequence is KCMY.
Black can be first or last as long as the tack is changed.
I got this information from a book titled Color
Control in Lithography by Kelvin Tritton, it's a great reference.
On the Black dot gain, one reason the Black gains the
most is because it hits all the other blankets going through the press, the
yellow has the least gain because it only prints on one blanket. The
exception is when the Yellow is printed at a higher line screen than the
other colors (to help morie problems). Actually the Yelo at a higher line
screen is quite common. (ie work is 175 line - Yellow is 200) Generally 25
lines per inch higher.
Dan Remaley
___________________________________________________________________________
Re: CMYK numbers
Posted by: "John Denniston"
Thu Jan 17, 2008 2:11 am (PST)
At 10:26 AM 1/12/2008 -0500, Terry wrote:
Also, before running off and making a
profile using these values (please tell me you're not
going to use
"Custom CMYK" to do this? Eek!), you need to
know what the expected
L*a*b* values of the solid primaries and secondaries
should be and
Are you suggesting that custom CMYK isn't capable of
creating reasonable separations assuming that the ink limits are known?
Regards,
John Denniston
www.dirtbikephoto.com
www.johndenniston.ca
www.dennistonphoto.com (Blog)
___________________________________________________________________________
Re: CMYK numbers
Posted by: J Walton
Thu Jan 17, 2008 2:11 am (PST)
Dan Remaley wrote:
Just a couple of points - PIRA the consulting,
training, and research group
in Europe researched the color
combinations of KCMY and KMCY. The results were that
the sequence of KCMY
is preferred - the reason is that when
Mag and Yel print together the "reds" are
better than when the Cyan is
between Mag and Yelo. In this sequence the greens
suffer a bit.
I got the sense that Dan and Terry were talking about
dot gain, not color sequence. So K>C>M>Y had to do with black
gaining more than cyan irrespective of order. Did I get that mixed up?
On the Black dot gain, one reason the Black gains the
most is because it
hits all the other blankets going through
the press, the yellow has the least gain because it
only prints on one
blanket.
So far I hadn't heard a reason why one color would gain
more than others, so it's good to hear one. That rationale makes sense if
you assume that black is going to go down first. Do you have any numbers
(in your experience) of what percentage of printers go black first? Has
anyone compared dot gain using different sequences?
What other reasons are there for dot gain to be greater
in any one ink? It would be great to get some data on that, because the
quote I hear at work quite a bit from "print experts" is that
magenta always gains the most. In fact a foremost "expert" likes
to say that gaming magazines run the magenta high because they want to make
all the blood look better. Apparently darker blood is better than neutral
grays. ;-)
If you can answer any of these questions that would be
great. I remember a friend of mine had you visit his company and said you
were very helpful in helping them fix their press set-up. Of course their
press set-up was ridiculously stupid to begin with, but you saved the day
nonetheless.
--
J Walton
___________________________________________________________________________
Re: CMYK numbers
Posted by: "John Romano"
Thu Jan 17, 2008 5:07 am (PST)
Has anyone compared dot gain using different sequences?
Yes, we have done some testing with running a Second
Black and Cyan. Basically running in this sequence KCMYKC, this was for a
Mottle test but I did Look at dot gain as well.
In all of the last down K and Cs they were printing
about 2 to 3 % sharper than The first down K and C.
This was run on a Sheetfed press with Linear plates,
Densities of the K and C Were the same for both the first down and last.
Also the CM, and CY Traps improved on the last down
sequence and the YM was not Changed.....obviously :)
One reason for different rotation would be Backtrap
Mottle in say blue backgrounds (sky?s and water ) And Release issues.
We run KCMY on almost everything.
Usually first down will have the highest gain, getting
hit by the most blankets.
--
John Romano
Acme Color Manager
G7 Certified Expert
Acme Printing Co. LLC
978-658-0800
___________________________________________________________________________
.
Re: CMYK numbers
Posted by: Jim Rich
Thu Jan 17, 2008 5:07 am (PST)
Hi Dan,
You comments are quite intriguing and I will definitely
find this book.
From what this book is suggesting or perhaps you also,
wouldn't it help to qualify this about dot gain. That is, the black and
yellow dot gain behavior might be as stated if everything else on the press
is working properly.
And if it is not then all bets are off.
For example, when I see the yellow at a higher line
screen, there is a good chance there is more dot gain than expected. That
is, instead of getting say a 17%, there might be 21% or even more.
Another observation, is that since yellow is the last
color down, this color in some cases has more dot gain because the yellow
ink takes on water because the paper does not hold the moister well and
drives the water in to the yellow ink, because yellow is the last color in
the sequence. I have seen this at the last 2 ot of 3 places I have been.
In those cases, there might be more dot gain for the
yellow.
I am sure mileage varies.
Jim Rich
___________________________________________________________________________
Re: CMYK numbers
Posted by: remaleydan
Fri Jan 18, 2008 3:36 pm (PST)
Yes, Jim absolutely true. The historic values to
achieve gray balance at press was the gain of Mag. and Cyan were the same
gain and black was +2% and yellow-2%, when printed at the right density. We
seldom curved film, but we could if we wanted to.
Dan
___________________________________________________________________________
Re: CMYK numbers
Posted by: remaleydan
Fri Jan 18, 2008 3:39 pm (PST)
On 1/17/08 1:25 AM, "J Walton" wrote:
I got the sense that Dan and Terry were talking about
dot gain, not
color sequence. So K>C>M>Y had to do with
black gaining more than cyan
irrespective of order. Did I get that mixed up?
If you run higher densities or ink film thickness- the
gain goes up. It1s the main reason that GCR doesn1t work in a print shop,
the printer doesn1t know his midtone dot gain. One reason is that the press
>manufacturer uses 20-40-60 in their color bar, no 50% to measure, so
they can1t measure.
So far I hadn't heard a reason why one color would gain
more than
others, so it's good to hear one. That rationale makes
sense if you
assume that black is going to go down first. Do you
have any numbers
(in your experience) of what percentage of printers go
black first?
Has anyone compared dot gain using different sequences?
Most printers run KCMY. Black is generally a ghosted
image, in fact, the black plate is the first thing I look at when I visit
the pressroom. If I see a ghosted black plate then I know all the color is
made of CMY and will show lots of color variation throughout the press run.
The number 1 reason for reprinting jobs - inconsistent color, not bad or
wrong color.
What other reasons are there for dot gain to be greater
in any one
ink? It would be great to get some data on that,
because the quote I
hear at work quite a bit from "print experts"
is that magenta always
gains the most. In fact a foremost "expert"
likes to say that gaming
magazines run the magenta high because they want to
make all the blood
look better. Apparently darker blood is better than
neutral grays. ;-)
Each manufacturer of ink is different, pigment load,
vehicles, and varnish are mixed differently. I have seen as much as a 6%
difference between >Cyan and Magenta with linear plates. I switched
printing units thinking it was the press, no it was the ink. People may say
that Magenta gains the most, but that1s not true. It is true that we are
real sensitive to Magenta dot gain changes, that1s why we print to gray
balance so there isn1t any hue shift. Here is a short list of items that
could affect dot gain- density, paper, fountain etch, water temperature,
ink-water balance, roller pressure, durometer reading, plate to blanket
pressure, blanket to impression cylinder pressure, etc.
If you can answer any of these questions that would be
great. I
remember a friend of mine had you visit his company and
said you were
very helpful in helping them fix their press set-up. Of
course their
press set-up was ridiculously stupid to begin with, but
you saved the
day nonetheless.
All printers should print to the same numbers, all the
scans and digital images are converted in Photoshop and there is a set of
printing numbers that match those conversions. You must print to gray
balance and you need a midtone 50C/40M/40Y patch on the color bar to prove
it - proofing too!
Dan Remaley
___________________________________________________________________________
Suitable GCR Defaults (WAS: CMYK numbers)
Posted by: Rick Gordon
Fri Jan 18, 2008 9:01 pm (PST)
Dan (Remaley),
Then is it your suggestion that a higher GCR (at least
medium) is more suitable to modern (i.e., well-controlled) workflows than
the often recommended light GCR or skeleton black?
I've often heard that using more GCR than defensibly
necessary (as for images with lots of near-neutral tones) can increase the
risk of dark prints if the K is run too heavy.
What is YOUR recommendation on what level of GCR to use
and when? (I've already got Dan [Margulis's] suggestions from his books.)
Rick Gordon
___________________________________________________
RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
___________________________________________________
WWW: http://www.shelterpub.com
III. Keeping B/W Images Consistent on Press
keeping b/w images consistent in CMYK
Posted by: "Lisa Kahane"
Tue Jan 22, 2008 8:34 am (PST)
Does anyone have experience publishing a book with a
blend of color and b/w images?
A printer I work with me tells me it's difficult to
keep the neutral color of the b/w consistent and suggests converting b/w to
grey scale and then to CMYK. Has anyone worked this way? Any other
suggestions? Would using the channel mixer help? My b/w files are rgb,
desaturated by a hue/sat adjustment layer.
Thanks for adding me to the group!
Lisa K
Lisa Kahane | photographer | 32 West 20 Street | New
York NY 10011 |
212.242.6496
___________________________________________________________________________
.
Re: keeping b/w images consistent in CMYK
Posted by: Henry Davis
Tue Jan 22, 2008 10:33 am (PST)
Lisa,
There must be some good stuff relating to this in the
archives, but basically, a cmyk image probably won't print totally neutral
throughout the tone scale without some special preparation.
For me, the best chance of maintaining a neutral cmyk
is to make sure that k is in the lead of the other three throughout the
tone scale of the image. Others will have their own preferences and
results.
It can be difficult to maintain neutral on press. If
you provide cmyk images that need to be neutral, then you will need to
prepare them in such a way as to stand a better chance. Also, greyscale
images should not be assumed to be inferior. Greyscale images have their
own look, and this look isn't always offensive.
It sounds backwards to me that the printer would
suggest that grey images converted to cmyk will somehow help them to retain
their neutrality. If the c, m and y ink is adjusted on press to make for
more favorable color images, this will not effect a greyscale image, but it
certainly will if these greyscale images have been converted to cmyk.
Henry Davis
___________________________________________________________________________
.
Re: keeping b/w images consistent in CMYK
Posted by: Lee Clawson
Tue Jan 22, 2008 10:33 am (PST)
Lisa,
Sounds like good advice.
Make a CMYK file the same size as the RGB. Copy the RGB
image (or an image converted to gray), then in the CMYK file go to the
Channel palette and select the Black channel. Paste your image into this
channel. The other channels (CMY) should be blank. When you go to press the
image will print with the black ink instead of needing perfect gray
balance.
Its not that gray balance is so hard but more that you
to minimize compromises to the color images with adjustments to make an
un-casted 4 color gray--
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Ron Kelly
Tue Jan 22, 2008 11:01 am (PST)
Lee:
This would give perfect neutrality, but wouldn't it
hurt image quality? The difference between 100K and a rich black would be
startling in a book with colour images, I should think.
As Henry Davis has suggested, CMYK from a greyscale
image is doable, and might be preferable. I would prefer to see better
quality at the expense of strict neutrality if it was my decision to make.
"Toning" the print towards sepia or some
other non-neutral black might help. That way, if the images are slightly
more or less "sepia" it wouldn't necessarily be obvious, page to
page, but they could still have a decent quality.
What do you think?
Ron Kelly
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: "John Romano" j
Tue Jan 22, 2008 11:01 am (PST)
If the printer is asking for CMYK, or Quadtones they
must have a good idea how a halftone will print. Most cases halftones run
light,washed out when they are inline with 4/color images.
I would convert to grayscale from the RGB, select all
and copy the channel.
Convert to CMYK, paste copied channel into ALL channels
and then Go into curves and bring down your shadow ends points on the CMY
to be 60,50,50.
If that?s too heavy reduce your CMY keeping the same
balance.
Your black will carry all of the shape and detail.
Save the curve if you have many images or option
command M will recall your last curve.
You could also ask the Printer how they run neutral
Quadtones, they may have their own recipe :)
John Romano
Acme Color Manager
G7 Certified Expert
Acme Printing Co. LLC
978-658-0800
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: "Preston Earle"
Tue Jan 22, 2008 11:58 am (PST)
My 2¢: The advantage to printing b/w images in
CMYK is that the CMY inks will provide extra density such that the printed
image will have a greater density range (more contrast) than one in K
alone. Unfortunately, if the image has a lot of middle tone, it will have a
lot of CMY middle tone that is very susceptible to tone shift when (not
"if") ink colors vary on press. I believe that anything you do to
reduce the possibility of this tone shift (by replacing CMY with K, for
example) will also reduce the benefit of replacing K with CMY. If the
images are mostly shadow, without much highlight and mid-tone, it might be
worth the compromise as tone shifts won't be very noticeable, but if they
are mostly highlight, the change to CMYK won't help the printed appearance
much. If they are mostly mid-tone, the risk of color shifts is great.
Preston Earle
www.sawdustforbrains.blogspot.com
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Lee Clawson
Tue Jan 22, 2008 11:59 am (PST)
on 1/22/08 2:55 PM, Ron Kelly wrote:
This would give perfect neutrality, but wouldn't it
hurt image quality? The
difference between 100K and a rich black would be
startling in a book with
colour images, I should think.
I agree completely. I stopped at giving her a way to
get the RGB to the black channel. Thought more info would get too complex
until we heard more about the project. Reading your comment makes me think
otherwise. Yes, it could be startling.
As Henry Davis has suggested, CMYK from a greyscale
image is doable, and
might be preferable. I would prefer to see better
quality at the expense of
strict neutrality if it was my decision to make.
"Toning" the print towards sepia or some
other non-neutral black might help.
That way, if the images are slightly more or less
"sepia" it wouldn't
necessarily be obvious, page to page, but they could
still have a decent
quality.
If Lisa can set the files up this way, in other words,
using 4 colors to extend the range of a straight grayscale print (from the
black channel) then I'm all for it. It would make a much better print in
the book.
Lisa, if you're reading this call your printer and ask
them about this idea.
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: "Pylant, Brian"
Tue Jan 22, 2008 1:43 pm (PST)
Make a CMYK file the same size as the RGB. Copy the RGB
image (or an image
converted to gray), then in the CMYK file go to the
Channel palette and
select the Black channel. Paste your image into this
channel. The other
channels (CMY) should be blank. When you go to press
the image will print
with the black ink instead of needing perfect gray
balance.
I'm confused (which is not unusual!)... how is this
different from supplying a greyscale image?
I use an action for four-color neutral images to move
most of the midtones and highlights to the black channel only, but leaving
CMY content in the darker mid-tones and shadow areas. I use the following
GCR to accomplish this:
GCR: Maximum
Blak Ink Limit: 100%
Total Ink Limit: 300%
UCA Amount: 50% (I have a second action with this set
to 25% as an alternate)
The result is an image that has all four inks in the
darker tones, providing depth and richness that a greyscale image cannot,
but removing most or all of the CMYK from the lighter areas where a color
cast due would be much more noticable.
It's certainly not going to eliminte any possiblity of
a color cast, only printing greyscale will prevent this with absolute
certainty. But for all the images I've used this method on, the results
were very satisfactory with only the slightest of casts at worst (and even
these looked very natural and intentional, perhaps a slight coolness or
warmness to the image but certainly not a "colorized"
appearance).
BRIAN PYLANT
Manager, Electronic Prepress
Disc Makers
7905 North Route 130
Pennsauken, NJ 08110
Toll free: 1-800-468-9353 ext. 5539
www.discmakers.com
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Jim Rich
Tue Jan 22, 2008 3:32 pm (PST)
Lisa,
I have some experience with book publishing with a mix
of gray and color images.
While I don't know all of the detail about your
project, it sure seems to be that your printers advice is not very good.
The reason for that is it is easier to print one color
for gray than 4 colors for gray.
However, it you go that way with 4 color gray you might
want to convert the grayscale images to color using a high level of GCR.
Jim Rich
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Stephen Marsh
Tue Jan 22, 2008 3:33 pm (PST)
Brian Pylant wrote:
I'm confused (which is not unusual!)... how is this
different from
supplying a greyscale image? <
The data should be no different, but the file size is
now larger (say 7mb instead of 2mb for a random image tested). Depending on
the application and CM behaviour, there can be different output of the
exact same tonal value if the CMYK working space and the Grayscale working
space are different, but this is often the exception and not the norm
(Acrobat composite prints can sometimes have this issue, where as printing
from less CM aware apps does not have this issue). So a grayscale 50% patch
may be different on the final print than a 4C 0cmy50k patch (colour
management is not perfect yet)!
The result is an image that has all four inks in the
darker tones,
providing depth and richness that a greyscale image
cannot, but
removing most or all of the CMYK from the lighter areas
where a color
cast due would be much more noticable.
I am sure that you meant to write "removing most
or all of the *CMY* from the lighter areas"...
Good advice, I agree that a mostly K image with some
neutral support screens for density in the darker areas is a very safe way
to play things, over and above custom CMYK heavy GCR.
Sincerely,
Stephen Marsh
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Dan Remaley
Tue Jan 22, 2008 9:18 pm (PST)
Absolutely right Preston, when you use GCR the Y-M-C
inks become more, or less saturated, moving the values away from the
dangerous midtone area. However, the Black becomes the midtone challenge,
but it's easier to watch one color than three! If the black is printed
wrong it's too light or dark which is OK to some degree, but when Y-M-C
change it's a hue shift and unacceptable. I show this in my Reference
piece, e-mail me and i'll send you a pdf.
Dan Remaley
___________________________________________________________________________
.
Re: keeping b/w images consistent in CMYK
Posted by: "Louis Dina"
Wed Jan 23, 2008 6:02 am (PST)
Brian, nice suggestion. I played with your approach
above and like the conversion results (at least on screen). I'll definitely
keep that in my tool box.
Thanks,
Lou Dina
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: "Pylant, Brian"
Wed Jan 23, 2008 3:35 pm (PST)
Depending on the application and CM behaviour, there
can be different
output of the exact same tonal value if the CMYK
working space and the
Grayscale working space are different, but this is
often the exception
and not the norm (Acrobat composite prints can
sometimes have this
issue, where as printing from less CM aware apps does
not have this
issue). So a grayscale 50% patch may be different on
the final print
than a 4C 0cmy50k patch (colour management is not
perfect yet)!
Gotcha... I don't usually think about that because when
I send files off (and when we receive them) I don't want any color
management applied, I just ask to honor the CMYK values I have provided,
unmodified. If I had sent a c0 m0 y0 k50 image and a k50 image, I would
expect them to print identically (and wouldn't accept any other result).
I am sure that you meant to write "removing most
or all of the *CMY*
from the lighter areas"...
HA! Yup, that's exactly what I meant... when I type CMY
my fingers just automatically throw the K on the end...
:o)
Brian, nice suggestion. I played with your approach
above and like the
conversion results (at least on screen). I'll
definitely keep that in
my tool box.
Thanks... I'm not sure where I picked up on this method
(very well could have been from this list!) but it seems to work well in
practice... the resulting printed images all seem to have the nice added
depth that you can only get from using four-color neutrals, but without the
inherent danger of a significant color cast.
BRIAN PYLANT
Manager, Electronic Prepress
Disc Makers
7905 North Route 130
Pennsauken, NJ 08110
Toll free: 1-800-468-9353 ext. 5539
www.discmakers.com
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Lee Clawson
Wed Jan 23, 2008 3:39 pm (PST)
Makes sense to me too. Lets wait till we hear more
about this book.
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
keeping b/w consistent in CMYK
Posted by: "lizziekpix"
Thu Jan 24, 2008 7:22 pm (PST)
OMG!
Now I have a better idea of why keeping a consistent
neutral tone is so difficult. I've copied everyone's posts and will study
them carefully for a consensus. My b/w images were shot on overcast days
and I've adjusted them to look lighter and brighter - the danger zone for
neutrality it seems.
The printer who suggested converting to greyscale - the
most limited colorspace- is not the one printing the book but someone who
successfully blended 4/c with b/w in CMYK for me on another project. The
printer for the book is in China. I've been promised two sets of proofs but
I want to learn as much as I can because the catalogue - printed without a
proof - is, well, uneven.
Thanks to everyone for their time and expertise.
Lisa Kahane
___________________________________________________________________________
.
converting rgb scans of b/w negs to grayscale
Posted by: lizziekpix
Thu Jan 24, 2008 7:22 pm (PST)
Thanks to everyone for the detailed answers to my
original question about keeping b/w images consistent in a CMYK
environment.
I've now been asked to convert my rgb scans of b/w negs
to grayscale. I do this in Photoshop using Image>Mode>Convert to
Profile>Working Gray-Dot Gain 20%. The AD didn't recognize this command
and asked me to use Image>Mode>Grayscale. She also asked me to submit
images without a color profile. Yikes!
Is there a substantive difference between these two
methods of conversion? Does one preserve more info than the other?
Thanks again. Sorry to tax the good will shown on this
forum.
Lisa Kahane
___________________________________________________________________________
.
Re: converting rgb scans of b/w negs to grayscale
Posted by: J Walton
Thu Jan 24, 2008 10:55 pm (PST)
On Jan 24, 2008 2:45 PM, lizziekpix wrote:
Thanks to everyone for the detailed answers to my
original question
about keeping b/w images consistent in a CMYK
environment.
You're welcome! Several good ideas/points/techniques
have come from the discussion.
I've now been asked to convert my rgb scans of b/w negs
to
grayscale. I do this in Photoshop using
Image>Mode>Convert to
Profile>Working Gray-Dot Gain 20%. The AD didn't
recognize this command
and asked me to use Image>Mode>Grayscale. She
also asked me to
submit images without a colorprofile. Yikes!
If they are grayscale images, that's fine. If they are
CMYK images and they are already prepared for those particular print
conditions, that's fine. If they are LAB images, that's fine. If they are
RGB, THAT'S NOT FINE.
Is there a substantive difference between these two
methods of conversion?
Does one preserve more info than the other?
Nope! When you use Image>Mode>[INSERT COLOR SPACE
HERE] you are using the workign profile specified in Color Settings
(Command-Shift-K). So going to Image>Mode>Convert to
Profile>Working space is the same thing, it just takes longer. It isn't
a bad idea, though, if you want to double-check the conversion before you
make it, or if you have a different profile as your default working space.
Thanks again. Sorry to tax the good will shown on this
forum.
Don't be silly. Questions about color, and how it
applies to printing, is the whole purpose of this list. Endless posts about
monitor calibration or "Why Dan is a Big Dummy Head" tax the good
will of the forum.
--
J Walton
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "jaysheela kumar"
Fri Jan 25, 2008 12:14 am (PST)
Hi,
I have small doubt "why it is consider converting
RGBto greyscale is not advisable.
it will be great if you could put some light on this.
Regards,
Jay
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Stephen Marsh
Fri Jan 25, 2008 12:14 am (PST)
Brian Pylant wrote:
Gotcha... I don't usually think about that because when
I send
files off (and when we receive them) I don't want any
color management
applied, I just ask to honor the CMYK values I have
provided,
unmodified. If I had sent a c0 m0 y0 k50 image and a
k50 image, I
would expect them to print identically (and wouldn't
accept any other result).
Agreed and understood, that is very common. If I
understand the situation with Acrobat, *composite* output is always colour
managed, so one may indeed get different results with Acrobat (untagged
data is assumed based on it's mode, which is where the discrepancies can
come in with gray vs. CMYK K only data).
The RIP that drives our large format inkjet can accept
PDF files simply by dropping them into a hot folder for processing, no need
to open Acrobat and print! Or is there? Results are different when printing
from Acrobat to the RIP using the same output settings, so it is obvious
that the RIP and Acrobat do not handle the composite data the same way.
Thanks... I'm not sure where I picked up on this method
(very well
could have been from this list!) but it seems to work
well in
practice... the resulting printed images all seem to
have the nice
added depth that you can only get from using four-color
neutrals, but
without the inherent danger of a significant color
cast.
On the Max CMYK/GCR sep, it may very well have been
from Dan or another list member here, who else would use custom CMYK, but
one of the dinosaurs found on this list? <g>
Were the print results sitting near full colour
originals, or was the only reference other rich gray images treated in the
same way? Due to the high K value and lower support tint values, there will
be better density than K only, but will they appear as dense as full colour
files that may also have a high (or lower) K value and higher CMY support
tint values? I can answer this with theory, but I prefer to hear from real
world results too!
Sincerely,
Stephen Marsh
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "Alex Kent"
Fri Jan 25, 2008 9:06 am (PST)
isn't this inviting unexpected Gamma shifts ? files
made at G2.2 and files made at G1.8 won't both print correctly side by side
if their profiles are lost.
alex kent.
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: J Walton
Fri Jan 25, 2008 9:06 am (PST)
There's nothing wrong with converting RGB to grayscale.
The sentence you are quoting above was in response to the printer's request
that images be sent without embedded profiles. You cannot send RGB out
without a profile, since the files will need to be converted to be printed
and in order to have a good conversion you need to know the source profile.
Grayscale and *properly-prepared* CMYK files can be printed without a
conversion (and sometimes embedding profiles can lead to unintended
disaster at the RIP). LAB files need to be converted as well but do not
have a profile to worry about.
RGB is another story.
--
J Walton
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "lizziekpix"
Fri Jan 25, 2008 9:06 am (PST)
Thanks, J Walton -
My files are RGB scans of b/w negatives. Are you saying
that I should convert them to CMYK or LAB before I discard all that lovely
info by converting them grayscale?
Thanks for reminding me that I need to ask which CMYK
profile to use for the 4/c images that will print in 4/c.
Lisa Kahane, photographer, NYC
PS All this pre-press work used to be someone else's
job, didn't it?
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "Paul D. DeRocco"
Fri Jan 25, 2008 3:16 pm (PST)
I would think an RGB scan of a B&W negative would
have essentially identical information in the three channels, but possibly
different noise. If one is distinctly noisier than another, I'd leave it
out and average the other two; if one is distinctly quieter than the other
two, I'd use it by itself. If they're all in the same ballpark, then
averaging all three would be best. Of course, if you've got visible film
grain, then the scanner noise may be insignificant.
--
Ciao, Paul D. DeRocco
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: Lee Clawson
Fri Jan 25, 2008 3:17 pm (PST)
on 1/25/08 12:13 PM, lizziekpix wrote:
My files are RGB scans of b/w negatives. Are you saying
that I
should convert them to CMYK or LAB before I discard all
that lovely
info by converting them grayscale?
Not sure I know what you mean. These are de-saturated
RGB files aren't they?. Besides the beautiful gray tones what else are you
talking about.
PS All this pre-press work used to be someone else's
job, didn't it?
Yes. That was awhile back. Call your printer and ask to
speak with the
pre-press people for more info about how to set up the
files and what they
expect to receive.
Oh, and this way its even easier than ever for the
photographer to get blamed for anything that goes wrong. :)
Lee Clawson
2/\V/\7 Studio
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: J Walton
Fri Jan 25, 2008 3:17 pm (PST)
On Jan 25, 2008 2:18 AM, Alex Kent wrote:
isn't this inviting unexpected Gamma shifts ?
files made at G2.2 and files made at G1.8 won't both
print correctly
side by side if their profiles are lost.
Remember that we are not talking about inkjet printing,
but offset printing. No matter what the gamma, a 25% value will be a 25%
dot on the plate*. A 50% value will be a 50% dot, and all the way through
the scale. The only reason to embed a profile is if you want those numbers
to change. If you have properly prepared the grayscale file for those print
conditions you don't want anything to change.
Don't think of it as losing the profiles, but rather
removing them to prevent problems down the road.
* Yes, I know that plate curves can affect this, if
they are used.
--
J Walton
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: J Walton
Fri Jan 25, 2008 3:19 pm (PST)
On Jan 25, 2008 8:13 AM, lizziekpix wrote:
Thanks, J Walton -
J is fine. Don't ask me why my name is only one letter,
it's my parents' doing. ;-)
My files are RGB scans of b/w negatives. Are you saying
that I
should convert them to CMYK or LAB before I discard all
that lovely
info by converting them grayscale?
Nope. I don't see why you would even want an RGB file
from a BW negative. Just convert away and make sure the Grayscale file
looks good.
PS All this pre-press work used to be someone else's
job, didn't it?
Actually it used to be my job before I started
concentrating on retouching. To be honest, I don't miss it, but it's good
to have a background in printing. ICC Profiles have made reproducing color
much easier but there are times when you need to know what a press is going
to do in order to prepare your files properly.
--
J Walton
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Henry Davis
Fri Jan 25, 2008 3:20 pm (PST)
On Jan 25, 2008, at 2:43 AM, Stephen Marsh wrote:
Were the print results sitting near full colour
originals, or was the
only reference other rich gray images treated in the
same way? Due to
the high K value and lower support tint values, there
will be better
density than K only, but will they appear as dense as
full colour
files that may also have a high (or lower) K value and
higher CMY
support tint values? I can answer this with theory, but
I prefer to
hear from real world results too!
This is a good point. The density is measurably
different, but it is slight, and varies with inksets. I wouldn't sweat the
differences between the full color image shadow areas and those of the
"rich grey" images. The viewer will already expect there to be an
overall difference between the two, as there should be.
To me, it would be odd that the viewer would even
suspect that anything is amiss in either of the shadows. As an observer
I've never considered comparing the shadow areas of color pictures with
those of neutral pictures - it's apples and oranges - they're supposed to
look different. I have measured the density difference, and that is one
thing. But, a measured density doesn't always relate to how we experience a
picture. The color casting of lighter tones would cause someone to suspect
that something is amiss, but if there is not an apparent cast, I doubt that
a casual observer would give the shadows a second thought.
Black ink alone might be found to range in density from
1.70 - 1.90, and an unprintable rich black of 400 percent might make 2.1.
Various printable rich black recipes will fall in between. Visually, it can
be very difficult to see the differences between them. A bigger concern
would be shadow detail, where there is a trade off with higher TIL. If
black is always leading the pack, then casting worries are less formidable.
The TIL will be most appropriate for the project when, for the
paper/ink/press combination, the desired detail and density are both
achieved.
Since there are a lot of factors, the basic guidelines
a shop recommends should be ok. But you have to keep in mind that these are
general guidelines - out of necessity. If one wants to fine-tune to find
the just-right combination for a certain project, then one might ought to
expect the accompanying costs and difficulties. Sort of like in a darkroom,
it will get down to the nature of the pictures, the results you're shooting
for and how much paper and chemicals you can afford to chase it. But the
just-right combination is out there.
Henry Davis
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "lizziekpix"
Sun Jan 27, 2008 3:29 am (PST)
Yes, all three channels look more or less alike,
although from time to time I picked up a color cast in the scan, perhaps
due to negative density, chemical residue, age (20+ years) or inexperience.
The film is mostly tri-x with visible grain, accentuated by sharpening, so
I'll need to look for scanner noise in the channels.
Thank You!
Lisa Kahane
___________________________________________________________________________
Re: converting rgb scans of b/w negs to grayscale
Posted by: "lizziekpix" l
Sun Jan 27, 2008 3:30 am (PST)
J- I was taught to make RGB scans of b/w negs because
more info is captured, the same reason I scan in 16 bit even tho I reduce
to 8 when I work. When I send images to other people's projects my RGB of
b/w work just fine. Perhaps I should compare a grayscale inkjet print to
one from RGB. My contract for this project calls for me to submit CMYK.
Guess they forgot about b/w. Which I still print in the darkroom.
Thanks!
Lisa Kahane
___________________________________________________________________________
.
Re: converting rgb scans of b/w negs to grayscale
Posted by: "lizziekpix"
Sun Jan 27, 2008 3:31 am (PST)
Lee Clawson wrote:
Not sure I know what you mean. These are de-saturated
RGB files aren't
they?. Besides the beautiful gray tones what else are
you talking about.
I was taught to scan b/w in RGB - more info, a richer
image. I save a layered file, with a channel mixer or desaturated
adjustment layer. When I sell b/w stock, I send a flattened RGB file. No
one has complained. Although I've seen some insensitive converstions - no,
wait, that was from 4/c.
PS All this pre-press work used to be someone else's
job, didn't it?
Yes. That was awhile back. Call your printer and ask to
speak with the
pre-press people for more info about how to set up the
files and what they
expect to receive.
The printer is in China. I'm working with the AD's
assistant at a publisher here in NY. They ran a teaser in their catalogue,
in CMYK, no proof. Three b/w images - three color tints. Because they'd
asked me to submit all CMYK for the book, I panicked. But it was just bad
communication - they need CMYK for the 4/c and grayscale for the b/w for
duotones.
Oh, and this way its even easier than ever for the
photographer to get
blamed for anything that goes wrong. :)
Ha, ha. You got that right, Lee!
Lisa Kahane
___________________________________________________________________________
Thanks!
Posted by: "lizziekpix"
Sun Jan 27, 2008 3:31 am (PST)
Thanks again to everyone for their answers about
grayscale and for the detailed discussion of b/w in CMYK. I polled my
friends and the folks I work with but no one had the answers until I found
this forum. You've made a nervous and overworked photographer very happy!
Lisa Kahane
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Stephen Marsh
Tue Jan 29, 2008 5:47 pm (PST)
Thanks for the detailed reply Henry. Agreed that the
density will be different, some clients *do/would* request the shadow
density differences to be less noticeable. Some also note that the mostly K
image has a more "coarse" dot structure in the lighter tones than
the CMY(K) rosette of a four colour grayscale.
I would probably personally use a higher UCA amount in
the Max. K sep. and to channel mix the support tints to be neutral for the
target print condition (based off assigned/assumed profile LAB readings).
Even though the K is much higher than the CMY support tints, it I prefer to
have things more neutral than 1-3 AB points off zero. Personally I would
add a touch more (K) dot gain to the separation, just in case and double
check the highlights just in case the Max. GCR step introduced CMY scum
dots, which sometimes happens.
Regards,
Stephen Marsh
___________________________________________________________________________
Re: keeping b/w images consistent in CMYK
Posted by: Rick Gordon
Wed Jan 30, 2008 4:03 am (PST)
Concerning the setting of UCA in other profile
generation applications, is there some means to control UCA (by some other
name) in ProfileMaker Pro 5? Would the black width setting affect this in
some translatable way?
P.S.: I understand that this may be pushing the limits
of the list, but since I am not aware of UCA being handled by applications
outside of Photoshop's legacy CMYK, and that is a last resort for many of
us who prefer other tools when then can fit the bill, I will plead my case
for the admission of this response.
Rick Gordon
--
___________________________________________________
RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
___________________________________________________
WWW: http://www.shelterpub.com
IV. Is This Total Ink Limit forReal?
.
Yet another CMYK separation question
Posted by: "michio sano"
Thu Jan 24, 2008 6:08 am (PST)
Hello people of ACT.
I am a bit confused about the separation spec on the
job I am working on, and I would like to seek some guidance from all the
experts here. This kind of issue may have been discussed before but please
bear with me.
Here is the situation.
I am working on a book cover image that is going to be
printed on coated 10pt C1s cover stock and will be gloss film laminated.
Proof will be printed with Epson / Oris system. I asked CSR of the printing
company for the spec and I was given the following spec:
US sheet fed coated, Dot gain somewhere 22 to 27 % and
TIL of 260%( 60C 50M 50Y 100K).
My problem is this 260% TIL. Isn't this unusually low
for coated sheet fed stock? Do they mean this just for Solid Black in the
graphic, or do I need to work within this limit even for a photograph? If I
separate the image using the specified profile, the black will easily go up
to 340 or so, and that's a huge difference. I tried two ways to work with
his parameter. First, I converted with US Sheetfed Coated v2 and pulled cmy
value with selective color. It didn't turn out quite well, So I, second
time, converted with custom profile, that more or less match the spec I was
given, and then assigned US Sheetfed Coated and tweaked to match the
original. It looks OK,and number is good. But it just didn't sit well with
me not knowing if this is really necessary....
What is everybody's take?
Any advice will be much appreciated.
Thank you!
Michio Sano-Giles
www.michiosano.com
___________________________________________________________________________
.
Re: Yet another CMYK separation question
Posted by: "John Romano"
Thu Jan 24, 2008 8:27 am (PST)
Hi Michio
That?s a pretty wide spread for Dot gain, 22 to 27 %
That and the 260 tac certainly sounds like an Uncoated stock.
I would ask someone else at the printing company, it
does not Sound like the CSR got you a good answer.
Yes that tac is way too low for Sheefed Coated sep.
Doesn?t sound right....Proceed with Caution !!
--
John Romano
Acme Color Manager
G7 Certified Expert
Acme Printing Co. LLC
978-658-0800
___________________________________________________________________________
Re: Yet another CMYK separation question
Posted by: "michio sano"
Thu Jan 24, 2008 11:18 am (PST)
John, thank you for your input.
I actually asked him to double check if this spec is
right for the paper.
And I received the following answer from the prepress
manager of the company:
" I think that our 'rich' black recommended
formula of;
60% Cyan
50% Magenta
50% Yellow
100% Black
For a total of 260% saturation is based on industry
standards and our experience."
I still think this is just for the solid black that
they are referring to.....What should I do?
Michio Sano
___________________________________________________________________________
Re: Yet another CMYK separation question
Posted by: "John Romano"
Thu Jan 24, 2008 1:59 pm (PST)
Hi Michio
Sounds Like they are referring to Black Tints, not so
much As images. Use the US Sheetfed Coated V2 like they asked.
In your original post they are saying to use that
profile, which is about 340 tac and then site the lower 260......and high
gain.
They must have meant under your blacks, not tac and yes
your correct with Thinking that its just for Graphics.
Sort of confusing the way it was put to you !
John
___________________________________________________________________________
Re: Yet another CMYK separation question
Posted by: "Louis Dina"
Thu Jan 24, 2008 1:59 pm (PST)
Michio,
Yes, the 260% is for their recommended rich black only.
That formula is very reasonable if you are building a solid black
background in InDesign, Illustrator, or even a border for pictures in PS.
It sounds like they are basically recommending US Sheetfed Coated for your
separations or working space, though their ink limits are a question, since
USSC is typically about 20%, with 350% TIL.
You could always ask them to provide a preliminary
proof (probably from their inkjet printer) and see how a standard USSC
separation prints. After all, it is their job to match their inkjet proof,
within normal tolerances, which unfortunately, are rather liberal.
Lou
___________________________________________________________________________
.
Re: Yet another CMYK separation question
Posted by: J Walton
Thu Jan 24, 2008 1:59 pm (PST)
I think you need to talk to them on the phone if you
haven't already, and just be clear on what you are discussing. His answer
(to me) is very clearly talking about a solid black tint, and not the TIL
of the images. Nobody's going to recommend 100% black for photography. In
fact, their solid black is a little higher than what I'm used to, which
tells me that their TIL may be 320 or even 340.
Perhaps they can give you a profile that they use, or
at least give you complete specs. A dot gain window from 22 to 27% is not
enough information to go on, and 60/50/50/100 is a solid black callout.
--
J Walton
___________________________________________________________________________
Re: Yet another CMYK separation question
Posted by: "michio sano"
Fri Jan 25, 2008 9:06 am (PST)
Thank you everyone for valuable advices.
After reading these threads, I spoke with the prepress
manager. It turned out that, she was indeed thinking about solid, rich
black, not four color photograph.
So, She says, for my purpose, it is 300% TAC.
that;s much more like it.
Again, thank you for your help!
Michio Sano
V. The Pressroom Blame Game
.
Pressroom blame game
Posted by: "Andy Adams"
Wed Jan 30, 2008 12:17 pm (PST)
I would like opinions on the following situation I find
where I work. I definitely have my own views, but will not express them so
as not to influence anyone's response.
For years the pressroom has jumped from one set of inks
to another and back again. They are also doing the same with chemistry,
etc. They claim this is because what they are trying to use "just
won't work" (the temptation to insert an opinion here is almost
unbearable). The result is a constant game of blame - whether it is the
paper, ink, chemistry, etc.
Now I don't doubt that sometimes such blame may be true
- to an extent. After all, there are many variables in the pressroom. But,
I have also worked in plants where the pressroom would do all they could to
stay consistant, and learn how to deal with the cards (ink, chemistry,
etc.) they were dealt.
Now I can keep the proofers consistantly making G7
proofs, but with the pressroom so disorganized, any compensation curves for
the plates will work one week but not the next.
So my question is this, what is your opinion on
who/what is at the root of the pressroom situation?
Andy Adams
P.S. I had tried to send such a question directly to
Dan Remaley, but it came back undelieverable. Who knows, maybe I was
considered "spam".
___________________________________________________________________________
Re: Pressroom blame game
Posted by: "PIA GATF"
Wed Jan 30, 2008 2:28 pm (PST)
Hi Andy, I run into this all the time, especially ink.
Quick ? what is the number one reason for selecting ink? Yep, price per
pound!!! Maybe the ink selected should be sent to our ink lab and measured
for water pickup, transparency, pigment load, drying speed, fade
resistance, etc. The price of the ink never includes run ability or mileage
information. So what is the true cost?
Edward Demming said to buy the most expensive that you
can afford. If you change inks on press, you need to develop new plate
curves for each color.
Dan Remaley
412.259.1814
___________________________________________________________________________
Re: Pressroom blame game
Posted by: "Romano, John"
Wed Jan 30, 2008 2:28 pm (PST)
Andy
You need to sit down with the pressroom forman and talk
to him. Have him read the G7 how to.Explain to him you need them to be
consistent with the inkset and chemistry.
One thing I always hear is"oh that wont make a
difference" and its usually by someone who doesnt measure anything.
Show them how your gains change from one inkset to the
other and what happens when there is a differnt chemistry being used.
You have to SHOW everyone what is changing and whats
not. Graph it out so everyone can see it....it will work trust me ! Measure
all of your press sheets and show em !
I feel your pain...been there
Root of the problem.....Press Room foreman , you could
start there ! If he doesn't listen just keep on going up !
John
___________________________________________________________________________
Re: Pressroom blame game
Posted by: Henry Davis
Wed Jan 30, 2008 2:29 pm (PST)
On Jan 30, 2008, at 8:52 AM, Andy Adams wrote:
Hah! Finding that it's easier to "calibrate"
a proofer than to "calibrate" a press? Only kidding. Sorry, I
just couldn't resist.
I'll give in to the temptation to respond without much
to go on.
There are justifiable reasons for using different
inksets and/or modifying their tack. Runability isn't usually a
consideration for proofers, but it is a big deal for press operators and
for the final printed results.
With a weekly change of inksets that are never the same
inksets, you may be spending more time running target sheets than jobs.
However, if it is always the same 3 or 4 inksets that are changed out for
runability reasons, then you can proof accordingly.
Perhaps some agreement could be had for settling once
and for all which inksets perform the best for certain substrates,
conditions and content - and stick with them. You can then predetermine
which kind of jobs will get which inkset, then schedule, proof and run.
Runability and the quality of the printed image have
nothing to do with matching the proof. Nothing. Sometimes there is a
tendency to be so proof-centric about color and so on that we forget that
there are important quality issues beyond these.
Whether there are personality or training concerns in
the pressroom is a different story.
Henry Davis
___________________________________________________________________________
Re: Pressroom blame game
Posted by: Jim Rich
Wed Jan 30, 2008 5:09 pm (PST)
Andy,
This is a management problem.
There are usually two people involved or sometimes
three . One is person who is in charge of the pressroom. He or she should
know better than to put so many variables into the mix that everyone in the
shop gets frustrated including the customers. Unfortunately some managers
don't get it, so it happens.
The second player is the person or persons who are
responsible for the printing company such as the plant manager or the
owner. If good leadership does not come from the top of a company, then a
mid level manager usually cant get the support. Then you can be in an
endless loop of frustration and problems. And of course, bad leadership
leads to a financial loss.
The third player in this type of saga is someone who
stirs things up. Some times they do it on purpose, sometimes it just
happens.
For this to go away the owner, or CEO has to put their
foot down hard and everyone needs to be come committed to making a positive
change. And as a lot of us know change is hard. And when some don't change,
they get canned.
The this type of change to work it often takes months.
My .02
Jim Rich
___________________________________________________________________________
Re: Pressroom blame game
Posted by: Terry Wyse
Wed Jan 30, 2008 5:10 pm (PST)
Do you know WHY they are constantly changing
inks/chemistry? What problem do they think they are chasing?
If they're not sure, then I think it would be time to
recommend bringing a real pressroom consultant, not a "color" or
calibration consultant (like myself), but a real pressroom
mechanical/chemistry guy that can really dig into what's going on. Get all
your current ink/chemistry suppliers involved as well. Everyone has a stake
in this.
From your standpoint as a prepress operator/manager and
"proof provider" for the pressroom, I would stick to your guns
and keep repeating the mantra of a STANDARD PROOF SPECIFICATION like
GRACoL/ SWOP/Fogra/whatever and just be prepared to VERIFY that you're
within a reasonable tolerance of that specification. It doesn't matter so
much WHAT the specification is, as long it's appropriate for your type of
printing/pressroom/paper combinations and that there is a characterization
data set and/or ICC profile that goes along with the specification you
choose (forget about a spec that only talks about density/TVI specs, it
doesn't work in today's world of inkjet proofing and color management).
As far as plate curves and/or press profiling goes, I
would take the position with your pressroom that, fine, go ahead and change
inks/ chemistry all you want as long as you give me ONE WEEK of
uninteruppted press time to re-calibrate the platesetter every time you
change a pressroom variable. Very like that will get the upper management's
attention and maybe they will put the kibosh on all this nonsense.
"Ink Da Jour" or the "Ink-of-the-Month
Club" is no way to run a pressroom.
Regards,
Terry Wyse
_____________________________
WyseConsul
Color Management Consulting
G7 Certified Expert
704.843.0858
http://www.wyseconsul.com
http://www.colormanagementgroup.com
___________________________________________________________________________
Re: Pressroom blame game
Posted by: "John Gallagher"
Wed Jan 30, 2008 5:10 pm (PST)
Andy,
I am very familiar with the situation. I have done G7
"calibration" in both pressroom and Prepress. And in prepress I
use Agfa's QMS-X Q.C. software and a spectro as well as X-Rites latest
Plate Dot reader to monitor plates. We do a good and thorough job of
process control for proofs and plates in prepress, yet the pressroom is
trying different inks on one day, different blankets, different stock,
etc., etc. This creates not just a moving target, but a target moving like
a scared Jack Rabbit. And who gets blamed when the pressman can't match the
proof?
Fortunately there are some enlightened pressman around
who understand the how and why of process control on an offset press. But
there aren't as many as there should be, and those that aren't enlightened
yet, need to be. GATF and RIT and G7 experts all can offer help here. I am
hoping in my situation to convince management of the need for an
independent (GATF) audit of our process control in prepress and press
departments so that the plant can hear the right message from someone else,
and someone unbiased.
In my previous shop we did NOT have these kinds of
problems. We ran three shifts on three multicolor presses. Everything was
standardized. There was NO experimenting done during production runs. Ideas
were suggested and if they seemed to make sense, controlled test runs were
scheduled to evaluate the product(s) or methods in question. Evaluations
were done, and usually further tests with other crews on other presses were
evaluated prior to a decision being made. The tests were to the best of our
ability done scientifically and often with some outside help for evaluation
of results. We evaluated the impact on quality as well as the impact on
other areas such as proofing. We also looked at the impact on productivity.
We particularly sought day after day reliability and consistency in the
products and methods we used, feeling these were keys to long term
productivity and to customer satisfaction. The extensive testing and
evaluation process also helped assure that when we did make a change,
everyone was on board and understood the rationale. We used the same
approach in other departments, not just the pressroom. I liked this
practical approach that encouraged improvement and experimentation but in a
controlled and planned way.
As far as who's to blame, etc., it doesn't really
matter. I do believe getting outside expertise can help get to real
solutions for real problems as opposed to arguing and playing the blame
game. Once personalities and feelings get involved and injured we start
expending more energy on the wrong things and it gets even harder to move
forward. When I am feeling frustrated by it all, I try to remind myself
that part of what I can contribute is some leadership, and that good
leaders do not inspire by calling people names or whining or feeling sorry
for themselves, but by bringing people together, seeking understanding,
seeking honesty, being positive, and by showing, not just telling of, a
better way. Somehow that pressroom and the prepress departments have to
realize they are both in the same boat (sharing responsibility for quality
and productivity in the print shop) and are responsible for it's arrival in
port. They therefore should start rowing together and in the same
direction.
Anyway, don't know if this helps at all, but I do hear
you! Good luck.!
John Gallagher
A Prepress Supervisor
Good luck
___________________________________________________________________________
Re: Pressroom blame game
Posted by: "PIA GATF"
Thu Jan 31, 2008 8:27 am (PST)
On 1/30/08 6:27 PM, "John Gallagher"wrote:
Fortunately there are some enlightened pressman around
who understand
the how and why of process control on an offset press.
But there
aren't as many as there should be, and those that
aren't enlightened
yet, need to be. GATF and RIT and G7 experts all can
offer help here.
I am hoping in my situation to convince management of
the need for an
independent (GATF) audit of our process control in
prepress and press
departments so that the plant can hear the right
message from someone
else, and someone unbiased.
I present a seminar on process control, when I visit a
printing plant, and help them develop standards, and plate curves. When I
do a TPA or TPM audit, I think it?s important for everyone in the plant to
understand the process. PIA/GATF even has a special program called ?TPM
Registry? which includes training, maintenance, calibration, and process
control for each piece of equipment. Yearly, a representative from PIA/GATF
will audit the facility for compliance. To my knowledge, this is the only
program of it?s kind. Once the process is stabilized we can develop other
programs such as Lean manufacturing. It is amazing to me that large
companies, with many plants, don?t utilize this service. I personally
visited all the Herff Jones printing plants and developed curves, and
introduced GCR so they all print the same. Now they can share jobs and be
more efficient - their make ready sheets and time were cut in half.
As far as who's to blame, etc., it doesn't really
matter. I do
believe getting outside expertise can help get to real
solutions for
real problems as opposed to arguing and playing the
blame game. Once
personalities and feelings get involved and injured we
start
expending more energy on the wrong things and it gets
even harder to
move forward. When I am feeling frustrated by it all, I
try to remind
myself that part of what I can contribute is some
leadership, and
that good leaders do not inspire by calling people
names or whining
or feeling sorry for themselves, but by bringing people
together,
seeking understanding, seeking honesty, being positive,
and by
showing, not just telling of, a better way. Somehow
that pressroom
and the prepress departments have to realize they are
both in the
same boat (sharing responsibility for quality and
productivity in the
print shop) and are responsible for it's arrival in
port. They
therefore should start rowing together and in the same
direction.
Printing is certainly a unique business, I wonder how
we get it right! I know of no other business where the Œcustomer?
brings you the raw materials (files,scans,fonts-sometimes) to produce the
job. If you want new cabinets for the kitchen do you go cut the trees down
and take them to the cabinet maker? Strange business, and since the
customer supplied the raw materials, he?s now part of your workflow! Good
or bad!
Please call with any questions. . . .
Dan Remaley PIA/GATF
412.259.1814
___________________________________________________________________________
Re: pressroom blame game
Posted by: "Kim"
Thu Jan 31, 2008 2:35 pm (PST)
Actually, Dan Remaley is the perfect person to deal
with this sort of situation. I do believe he is on this list and will reply
to it. I will forward to him just in case.
Good luck!
Kim Lathan
Quality Analyst
___________________________________________________________________________
.
Re: Pressroom blame game
Posted by: "Andy Adams"
Mon Feb 4, 2008 7:27 am (PST)
I just wanted to thank those who took the time to
respond to my topic. What was said is what I and others here have been
saying for quite some time. The powers that be listened.
At any rate, thanks. And to you Mr. Dan Remaley, you
may be hearing from my boss in the near future.
Andy Adams