From: Dan Margulis
Date: Wed, Nov 24, 1999, 5:50 PM
RE: Dot gain, whose responsibility?
Folks,Responses to my recent articles on dot gain indicate that there is still a lot of confusion among users (and printers, apparently) about what the Photoshop settings do. Here's one note I received recently; I'm posting my answer separately.
Dan Margulis
******************
Hello Dan,Great article in Electronic Publishing on Dot Gain. However, I have a few questions I was hoping you would kindly answer.
My commercial printer indicated that any dot gain settings I make in Photoshop will not be used. When they RIP the Quark file they apply their own dot gain settings based on the press, line screen and paper. They said any dot gain settings we made will only affect how the image looks on our screens.
1) Is the printer correct that my dot gain settings have no affect since they apply their own?
2) Is dot gain to make images look correct on screen or to make them print properly? I always thought it was for the latter but the article seems to imply both.
Thanks,
From: Mac Townsend
Date: Wed, Nov 24, 1999, 6:35 PM
Re: Dot gain, whose responsibility?
Many RIPs these days include multiple levels of what I tend to call "linearization", or using lookup tables to get a PS call for a 10% dot to actually print at 10%. (some might call this calibration, but I think that's a different process: is a laser's projection on the film a "spot" as Lino and others claim, or must we accept Blatner & Roth's saying that is a "dot?" Ultimately it makes no difference, so long as the context makes the meaning clear.).The intent of these "calibrations" is to make similar lookup table adjustments based on the specific press to be used. I suspect the only really proper use of these would be in CTP or a digital press rather than to film (at least in a general situation such as mine); and indeed, Harlequin (the one with which I'm familiar) is used pretty widely in both applications. They even include the ability to set different factors for different inks.
I suspect that this is what the printer was talking about, not the RGB>CMYK conversion issues within Pshop.
Mac Townsend,
Adcom Graphics, Fairfield, CA:
www.adcomgraphics.com
A Corel Platinum Service Bureau
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Wed, Nov 24, 1999, 5:52 PM
RE: Dot gain, whose responsibility?
>>1) Is the printer correct that my dot gain settings have no affect since they apply their own?>>If you are supplying them RGB files, the printer is correct. The settings only have an impact on printing at the moment of separation. If you are supplying the printer RGB, that moment takes place at some point in the future and the printer is responsible. If you are supplying CMYK, that moment took place in the past, and your printer's advice is incorrect.
>>2) Is dot gain to make images look correct on screen or to make them print properly? I always thought it was for the latter but the article seems to imply both.>>
When you are in RGB, which has no inks and therefore no dot gain, the dot gain setting is an effort to make the separation print properly, when you finally make the separation. Once you are in CMYK, the only function is to make the screen look correct.
Example: you have dot gain set at 20%, but as it happens it should really be at 30%. Three workflows:
1) You convert the RGB file at 20%. The resulting CMYK now looks like the RGB file. However, it will print too dark.
2) You convert the RGB file at 20%, and then change the dot gain setting to 30%. Now the CMYK looks darker than the RGB, accurately reflecting that this is the way the job will print.
3) You change the dot gain to 30% before converting. The CMYK file now looks like the RGB, *and* it prints correctly.
4) you change the dot gain to 30% before converting, but back to 20% afterward for some reason. The CMYK file now looks lighter than the RGB, but this is a lie, as it will print correctly.
Dan Margulis
From: Dan Margulis
Date: Thu, Nov 25, 1999, 12:27 PM
RE: Re: Dot gain, whose responsibility?
Mac writes:>>Many RIPs these days include multiple levels of what I tend to call "linearization", or using lookup tables to get a PS call for a 10% dot to actually print at 10%. (some might call this calibration, but I think that's a different process: is a laser's projection on the film a "spot" as Lino and others claim, or must we accept Blatner & Roth's saying that is a "dot?">>
The terminology is very confusing. I favor the use of the term "spot" to mean the smallest area addressable by the imagesetter, which is typically .001 x .001 mm or something along those lines. Those spots are used to create a larger element called a halftone dot; if that's what David and Steve are calling a dot, I agree. So, I would say, a 2540 spi imagesetter creating a 150 dpi screen, but lots of other people use different terms.
>>The intent of these "calibrations" is to make similar lookup table adjustments based on the specific press to be used. I suspect the only really proper use of these would be in CTP or a digital press rather than to film (at least in a general situation such as mine); and indeed, Harlequin (the one with which I'm familiar) is used pretty widely in both applications. They even include the ability to set different factors for different inks.>>
The practice is actually much wider than this, and has been commonly used in digital proofers, color copiers, and in preparation of gravure halftones for many years. This is exactly what a lot of people now do with ICC profiles. Here is one area where, although it's analogous to the traditional method and in principle no better, using the ICC format has an advantage. You don't have to learn six different calibration methods for six different devices.
>>I suspect that this is what the printer was talking about, not the RGB>CMY conversion issues within Pshop.>>
If he was, he's still wrong. If a pixel comes in with a value of18% his method may knock it down to 15%, but it has no idea of how the original 18% was produced. That original 18% is dependent on the customer's own dot gain setting, and if that setting is inappropriate the color will be wrong.
All that the internal calibration does is to make the output device, whatever it is, look more to the user as though it conforms to SWOP, whatever that is, rather than its natural behavior, whatever that is. Probably he originally tried to calibrate to somebody else's Matchprint.
In short, you probably start with a device that could have anything between 10 and 40% dot gain. The printer's calibration will cut out some of the extremes, so maybe now it looks to the user as though it's anything between 15 and 25%. That's still an enormous range, and the user should be prepared to adjust his own dot gain setting to compensate.
Dan Margulis
From: paul white
Date: Mon, Nov 29, 1999, 11:47 AM
RE: Re: Dot gain, whose responsibility
as written by Dan Margulis>1) You convert the RGB file at 20%. The resulting CMYK now looks like the >RGB file. However, it will print too dark.
>2) You convert the RGB file at 20%, and then change the dot gain setting to >30%. Now the CMYK looks darker than the RGB, accurately reflecting that
>this is the way the job will print.>3) You change the dot gain to 30% before converting. The CMYK file now
>looks like the RGB, *and* it prints correctly.>4) you change the dot gain to 30% before converting, but back to 20% >afterward for some reason. The CMYK file now looks lighter than the RGB,
>but this is a lie, as it will print correctly.Thanks Dan, this puts the method of calibrating for dot gain into crystal clear focus.
/// ///
/// Paul White ///
/// Advertising ///
/// Story House Corporation ///
/// Bindery Lane ///
/// Charlotteville, NY 12036 ///
I realize this isn't a color question, but I think some of you may still have some suggestions.
I've got a job going to press this week that being printed bw on uncoated newsprint. I'm trying to find out if this is the real cheap grayish newsprint, or the slightly whiter variety as I type. 85 lpi halftones, so I'm figuring 170 dpi or lower on resolution at 100percent size.
In the past I've used a maximum black of about 82-85 percent black, and a maximum white of about 4 percent black (unless it's a specular highlight). I bring the midtones up about 10-20 percent (a 50 percent patch gets placed about 40-45 percent).
I've had varying results with these settings, and suspect much has to do with the fact that they have been printed at different presses. I've already talked to the printer, and they don't have any idea for settings. Whenever they have digital files they send them to a local blueprint/service bureau shop for imaging to paper (not film). The blueprint/service bureau claims that they don't do any adjustments to the files, and don't want to give out their clients names (lots of help).
I only do print jobs for newsprint about every other blue moon, so would appreciate any help from the collective wisdom.
TIA,
David
David Riecks * david@riecks.com
701 W. Washington St * Midwest/Chicago ASMP
Champaign, IL 61820 *
ph/fax 217-239-FOTO(3686) * http://www.riecks.com/
From: Christine Holzmann
Date: Tue, Jan 9, 2001, 10:13 PM
RE: Re: [colortheory] Optimal TAC, dotgain for B/W, newsprint
David,
I work with newsprint and my color is excellent. When I began with newsprint, I had a LOT of questions to ask about the color and settings and got a lot of very excellent advice from Dan Margulis's book: Professional Photoshop 5. Anyway, to get to the point, I shall tell you what settings I use and what I have found to be optimum for newsprint. One of the MOST important settings to take into consideration for newsprint is the DOT GAIN. The standard dot gain I would use would be 34%. I then change over to the curves settings for the dot gain and input the following settings at the 50% point for each plate:
CYAN = 84
MAGENTA = 84
YELLOW = 82
BLACK = 88
(I had calculated my settings according to Dan's advice in one of his columns when Photoshop 5 first came out. Basically, you add "50" to your standard setting of "34" to the CYAN and MAGENTA (50 + 34 = 84), you minus two points from that number for YELLOW (84 - 2 = 82) and then instead for black, ADD 4 points to that number (84 + 4 =88). I am not going to go into an explanation as to why...I am strapped for time right now....:(TAC = 260
Black ink limit = 80
I prefer to use UCR for newsprint....you get the skeleton black plate that way with less muddiness.85LPI is perfect.
170dpi is also perfect.
Maximum black....85% percent is good.
Maximum white.......4 or 5% is good. (For color a lot of the time I can "blow out" the highlights to make it look even better.)As for the pressman, you are absolutely correct about different pressmen using different methods.......on some days of the week, our paper used to get printed REALLY dark with too much ink while on other days, it was printed a lot lighter. This happened on a regular basis tho' and the way I compensated for it was by adjusting the TAC settings. One the days I knew the paper would be printed darker (which was every Friday) I would set the TAC to 240. On the other days, I would use 260. Basically now our paper is always printed the same (not the over dark way) so I stick to a TAC setting of 260. So basically, between 240 and 260 would be your optimum range.
Hope I was able to help......it seems tho' that your settings and methods are already great the way they are....:)
Good luck!!
Crissi
From: Stephen Marsh
Date: Thu, Jan 11, 2001, 4:34 AM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W, newsprint
David, I use an 'unscientific' eyeball/info palette method - which gets me by without any real shocks when the paper comes off the press.I use a custom action to convert colour originals to to greyscale mode snapshots - I then simply select the 'best' looking one from 5 or 6 different conversion methods.
These actions use 30% newsprint dot gain settings in the conversion from RGB to greyscale - and the Greyscale setup in Photoshop 5.5 is set to Black Ink.
But these images are still too dark. So I use curves in the action to reduce the tones for printing.
I set non detail highlights to around 3-5% and shadows to 80-85%. The mid/quarter/three quarter tones are usually pulled down as well. Usually the 50% point ends up being around 35%.
This image is also previewed without black point compensation if using the ICC CMYK setup. Tones may appear light on screen, but with the info palette you can see what your true tones are.
I no longer get prints which are too dark, and the paper must love my 'grey' images which are not too black for them to print. Perhaps I am too conservative with my settings and things could be darker...
Take what you want from this post, I'm sure the forum will spot any holes in my approach.
Hope this helps,
Stephen.
From: Stephen Marsh
Date: Thu, Jan 11, 2001, 4:05 AM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W, newsprint
Firstly, I know that talking about colour is 'off topic' to this
post, so I will respond to the original message regarding monotone work.I have a question for Christine or anyone else who would care to comment.
--- In colortheory@egroups.com, Christine Holzmann wrote:
> TAC = 260
> Black ink limit = 80
> I prefer to use UCR for newsprint....you get the skeleton black
plate that way with less muddiness.
Christine, I do both mono & colour news separations each week for local and city papers - I am hoping to pick the lists collective mind on this subject, and this seems like a good opening...
No paper we deal with in Sydney seems to offer sep tables or ICC profiles for their material suppliers. When they do give specs, they are contradictory or are aimed at the traditional separator or drum scanner operator.
I am the first to admit that I know just enough to be dangerous, but to me MEDIUM GCR is not 70% replacement?
As far as I know, Photoshop does not deal in numerical values by default, it has none, light, medium, heavy and maximum GCR levels.
I guess and presume that none is 0%, light is 25%, medium is 50%, heavy is 75% and maximum is 100% GCR...I am probably way off base here, and I'm sure that I will be corrected by those who know better.
For our printers, grey balance and registration seem to be a common problem - not to mention consistent dot gain.
I commonly use these settings:
SWOP Newsprint 30% Dot Gain
GCR separation type
80% Max Black
230% Max Ink (TIC/TAC/etc)
Heavy Black generation
0% UCAThis cures most registration and colour balance problems, as most of the neutral tones are in the black plate.
I think that MAX GCR and 30-50% UCA *might* be the answer, but this
is too radical from my experience to trust to a live job.I also must have the dot gain wrong, as images still need curves adjustments to lighten the tones throughout the image - otherwise it just runs too strong.
Also for a 85-100 lpi screen, I have found that you can sometimes go as low as 100 ppi when the image is S/S (same size).
Some newspapers use JPEG internally in their FTP, so images get degraded further, whether you like it or not (but considering the output, this does not really matter).
Can anyone comment on my choices for colour newsprint work, or give some rationale to why other settings should be used?
Image content varies, and is too numerous to describe. I realise that there is no magic 'single setting' for all images, but there must be some rules to follow (I will shortly purchse Dan's book, as it seems that the answers to many of my questions will be found there).
Thanks,
Stephen Marsh.
From: Christine Holzmann,
Date: Thu, Jan 11, 2001, 12:51 PM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W newsprint
To all,
I just want to apologize for not having yet responded to some of your queries/comments. I am still going to add some comments in this area, as it is a REALLY important topic to me as it is to all of you.......I am just on deadline right now and don't have a split second to spare until tomorrow or so..........:(Crissi
-- DESIGN EDITOR @ The Citizen News
http://www.thecitizennews.comDIGITAL/GRAPHIC ARTIST
http://www.crissi.com
From: Dan Margulis
Date: Thu, Jan 11, 2001, 2:43 PM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W, newsprint
Stephen writes,>>I guess and presume that none is 0%, light is 25%, medium is 50%, heavy is 75% and maximum is 100% GCR...I am probably way off base here, and I'm sure that I will be corrected by those who know better.>>
This is way off base. GCR is too complex to be described by a single number. It's basically a combination of 1) what is the lightest gray component at which black starts to appear; 2) how rapidly does black increase in relation to CMY thereafter; 3) how the shadow is treated when we start to get close to the ink limit.
>>I commonly use these settings: SWOP Newsprint
30% Dot Gain
GCR separation type
80% Max Black
230% Max Ink (TIC/TAC/etc)
Heavy Black generation
0% UCA>>Heavy black generation isn't standard although some use it successfully. 230 max ink is too low. Most newspapers say they'll accept 240, which means they'll accept 250. So, I'd move it up at least to 245.
>>I think that MAX GCR and 30-50% UCA *might* be the answer, but this is too radical from my experience to trust to a live job.>>
This will definitely *not* be the answer. Maximum GCR is not usable, IMHO, for serious reproduction of photographs. Its function is for the rare cases.
>>I also must have the dot gain wrong, as images still need curves adjustments to lighten the tones throughout the image - otherwise it just runs too strong.
What you probably have wrong is the *black* dot gain, which is ordinarily higher than that in CMY. Couple that with the heavy black generation you're using, and the image will be too dark. The overall dot gain may be too low, but the black is too low for sure.
>>Also for a 85-100 lpi screen, I have found that you can sometimes go as low as 100 ppi when the image is S/S (same size).>>
This is image-specific. The more fine detail there is in the image, the more conservative one has to be with resolution. 150 should be fine for the overwhelming majority of images, but for images that are softer by nature one can go lower, and 100 isn't unreasonable. I've seen plenty of successful results where the resolution is actually *less* than the screen ruling, but it takes a certain kind of image.
Dan Margulis
From: Stephen Marsh
Date: Fri, Jan 12, 2001, 7:46 AM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W newsprint
Thanks, Dan.So it seems that by trying to cure one problem, I was creating other problems.
I originally started with light GCR settings, but due to registration problems the newsprint images would get very blurry and out of focus. I know that web presses can't hold rego as well as flat sheet, so this is something that I will just have to accept. I originally tried light/med. black generation, but was not happy with the inconsistent results - so more black and less neutral CMY seemed to be the other logical extreme to try...oh well.
So it seems that I will need to look at slightly higher total ink limits and either Light GCR or UCR. Some papers quote 220-240%, so I was striking a happy middle ground with 230%...but you're correct, this can be run slightly higher - I was just playing things safe.
You also mention higher dot gain in the black plate. Would you suggest setting this as a custom dot gain curve, or pulling down the curve manually in the K channel?
I also have the same question, in regards to max K limits...Generate a file with 100% K and hand tweak the K plate with curves, or set the CMYK setup for K: 80%, 70% etc
Personally I would trust Photoshop's conversion of black dot gain and max black limits, over my hand tweaking with curves - but from reading your 'by the numbers' approach it seems that I should put more trust in myself - if I follow the info readout and keep the balance of C to MY slightly higher.
So if I understand you correctly, using a 'skeleton' black as in Light GCR or as found in a UCR separation - you can confidently change the black plate for the extra expected dot gain, without concern for altering the neutrality of the image, which is mostly made of CMY inks.
I am not 'new' to print, but I am new to the 'science' and the practical side of colour separation (my typesetting background has evolved into broader pre press, but I sadly lack the formal trade training in graphic reproduction).
Thank you for your thoughts and experience.
Stephen Marsh.
From: Dan Margulis
Date: Fri, Jan 12, 2001, 10:29 PM
RE: [colortheory] Re: Optimal TAC, dotgain for B/W newsprint
Stephen writes,>>I originally started with light GCR settings, but due to registration problems the newsprint images would get very blurry and out of focus. I know that web presses can't hold dots as well as flat sheet, so this is something that I will just have to accept. I originally tried light/med. black generation, but was not happy with the inconsistent results - so more black and less neutral CMY seemed to be the other logical extreme to try...oh well.>>
There is a lot of merit in this position. This is why I said that Heavy GCR is nonstandard, and not that it's bad. The pluses of more GCR are better registration and less color variation. The big minus is that you are at the mercy of the black plate, and if it prints too heavily (or if you underestimate its dot gain) this can ruin the image fairly easily.
>>You also mention higher dot gain in the black plate. Would you suggest setting this as a custom dot gain curve, or pulling down the curve manually in the K channel?>>
The dot gain curve. Why go to the extra work of doing manually it each time?
>>I also have the same question, in regards to max K limits...Generate a file with 100% K and hand tweak the K plate with curves, or set the CMYK setup for K: 80%, 70% etc.>>
Same answer, but stronger: if you have a 100% black ink limit, the shadow value in CMY will be artificially low, which causes difficulties in the correction process later on.
>>Personally I would trust Photoshop's conversion of black dot gain and max black limits, over my hand tweaking with curves - but from reading your 'by the numbers' approach it seems that I should put more trust in myself - if I follow the info readout and keep the balance of C to MY slightly higher.>>
Keeping that balance has nothing to do with black generation. If it isn't balanced in RGB, you're going to have to correct it sooner or later no matter what kind of GCR you use, and if it is balanced in RGB, nothing you can do with the black channel will unbalance it.
>>So if I understand you correctly, using a 'skeleton' black as in Light GCR or as found in a UCR separation - you can confidently change the black plate for the extra expected dot gain, without concern for altering the neutrality of the image, which is mostly made of CMY inks.>>
Same as above. GCR or lack of it will not alter the neutrality of the image. You can be confident that black dot gain is heavier than the other three in newspaper printing. You should correct that no matter what kind of GCR you use, and you should correct the Photoshop error that has cyan with more dot gain than the others.
While increasing the black dot gain setting will surely improve things, it will improve things *less* if you use a skeleton black. The black channel will be lighter by nature, so the impact of any mistake, either in printing or prepress, will be less.
The thing to do now is assemble some images that have printed already, and view them on the screen. Reduce the black midtone in all of them by four points. This will presumably give a more accurate preview. Once having saved this change, also reduce the CMYK master curve by two points and ask yourself whether this has made most of the images more accurate. If it hasn't, this suggests that your 30% dot gain figure is correct. If it has, you need to adjust your overall dot gain up by at least two points. One way or another, when you choose your final dot gain figure, you should start with C=M=Y=(K-4).
Dan Margulis
From: Stephen Marsh
Date: Sat, Jan 13, 2001, 9:29 PM
RE: [colortheory] Optimal TAC, dotgain for B/W, newsprint - Cheers!
Dan wrote:> > There is a lot of merit in this position. This is why I said that Heavy GCR is nonstandard, and not that it's bad. The pluses of more GCR are better registration and less colour variation. The big minus is that you are at the mercy of the black plate, and if it prints too heavily (or if you underestimate its dot gain) this can ruin the image fairly easily.>
Thanks Dan, this is making more sense to me now. After reading chapter 6 'In Colour Correction, The Key is the K' in your book, I can now see many more uses - both technical and artistic, for the black plate in more regular printing than newsprint. I'm sure that when I finish chapter 12 I will have an even better grasp of your points in regards to dot gain and the use of black.The other answers to my questions also helped a lot as well. Cheers. I only got my copy of PP6 yesterday, and have decided to read it cover to cover before going back and following all the examples one by one (I need 'hands on' practice to make the principles sink in -before being put to use on a real job - so kudos to you for including the CD in this issue - sometimes the file you use to demonstrate is better for the education process than trying to find one - or worse, waiting until a client needs it done and you have no experience). I use APS4 and 5, but so far there does not seem to be too many APS6 specific tools - but as you say, the principles can usually beapplied to any version or similar software. Once again, thanks for your time and congratulations on the latest book - I am VERY happy with the purchase.
Regards, Stephen Marsh.
DanI am a digital photographer and have read all your books, and numerous others on preparing photographs for print. the question I have is a very basic one concerning dot gain and the proofing process. I am a prepress “outsider.” having never worked in that area other than handing off the photos to an AD or sometimes directly to a print firm. One prepress manager told me that their Fuji proof system had 2 “settings” for dot gain, and I believe the lower one would reflect a DG of 12-18%. He told me that after the proof stage the entire job would be processed through a curve (ripped?) that would incorporate paper and press specific dot gain (and other) attributes. I guess their scanning would then be done toward that 12-18% DG.
If this was so, then if I do a conversion in Photoshop for a higher dot gain scenario, say, SWOP uncoated's 25%, then the photos would be much too light.
I need some illumination here.
Les Schofer
Schofer Digital
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Tue, Mar 21, 2000, 1:50 PM
RE: Re: dot gain and Matchprint
>>If this was so, then if I do a conversion in Photoshop for a higher dot gain scenario, say, SWOP uncoated's 25%, then the photos would be much too light>>yeah so don't use SWOP uncoated 25% dot gain to make your separations. If you can get a Fuji ColorArt profile (I think I have one but I haven't ever used it, so I don't know how bad or good it is; and I have no idea what dot gain it simulates), use that for making separations.
The service provider needs to do one of two things:
1.) Provide you with a Photoshop separation table or ICC profile for their contract proofing system of choice.
2.) Accept RGB images from you and separate them properly themselves.
#2 is becoming more common as service bureaus see the end of their CMYK only world coming to an end (i.e. where they provide the digital images from drum scans) but I wouldn't bet on it. The average service bureau is scared to death of RGB images and wouldn't want to be responsible for making separations from them.
#1 you have marginally greater luck with; it's pretty common for service bureaus to have their profiles built into their heads, or in proprietary systems and not in a Photoshop separation table or ICC profile.
Therein lies the weakness of today's workflow. They won't accept RGB, but only CMYK, but they won't tell you how to get it into CMYK properly. It's a great way to justify paying them to fix it when that's the only way to get it done.
So the ideal is #2, and #1 is sufficient, and the other option is to just notch down dot gain in Photoshop 5's CMYK setup to around 16%, make your separation and get a Fuji proof and see where you're at. In other words, you just muddle through. But I'd still give them a hard time about #1 and #2, service bureaus need to realize they need to be doing one or the other or color quality is going to go downhill really fast as customers start providing digital files and the SB's aren't making the scans.
Chris Murphy
From: Lee Blevins,
Date: Thu, Mar 23, 2000, 6:59 AM
RE: Re: dot gain and Matchprint
>>#2 is becoming more common as service bureaus see the end of their CMYK only world coming to an end (i.e. where they provide the digital images from drum scans) but I wouldn't bet on it. The average service bureau is scared to death of RGB images and wouldn't want to be responsible for making separations from them.>>Where do you see this CMYK world coming to an end?
Did someone invent an RGB printing press?
Are “contract quality proofs” now including RGB proofing systems?
We are not “scared to death” of RGB images. We know quite well what they are and the risks associated with accepting them. At my shop we are well informed on color management, we have the technology and we've evaluated the results under controlled systems.
Our problem is “the buck stops here.” Claims of color matching have to become reality or the customer might not pay.
It's one thing to write articles and evangelize, totally another to stand in the viewing booth with the customer and discuss the print.
From: Bob Smith
Date: Thu, Mar 23, 2000, 7:46 AM
RE: Re: dot gain and Matchprint
Lee Blevins wrote:>>We are not “scared to death” of RGB images. We know quite well what they are and the risks associated with accepting them. At my shop we are well > informed on color management, we have the technology and we've evaluated > the results under controlled systems.
Thats wonderful, but in my admittedly limited experience thats certainly not the norm. “Scared to death” may not be an appropriate description... “don't have a clue” might be better; but I otherwise agree with Cris's assesment. I've dealt with many traditional prepress shops that will do a beautiful job if you provide them CMYK material... even BAD CMYK that they are given an opportunity to correct. However the majority of those same shops will completly choke when given RGB input. I see this changing slowly. More and more of the traditional prepress shops are becoming more RGB fluent and its probably being driven by demand from clients that are increasingly using high-end rgb output devices as well as CMYK. You see many traditional primarily RGB shops like photolabs getting into prepress in one way or another and many traditional prepress shops adding devices that are primarily RGB driven. I think all of this is driven by customers that want a variety of output and don't want to deal with several providers to get it.
Bob Smith
From: Dan Margulis, INTERNET:76270.1033@compuserve.com
Date: Thu, Mar 23, 2000, 12:01 AM
RE: dot gain and Matchprint
Les writes:>>I am a digital photographer and have read all your books, and numerous others on preparing photographs for print. the question I have is a very basic one concerning dot gain and the proofing process. I am a prepress “outsider.” having never worked in that area other than handing off the photos to an AD or sometimes directly to a print firm. One prepress manager told me that their Fuji proof system had 2 “settings” for dot gain, and I believe the lower one would reflect a DG of 12-18%. He told me that after the proof stage the entire job would be processed through a curve (ripped?) that would incorporate paper and press specific dot gain (and other) attributes. I guess their scanning would then be done toward that 12-18% DG.>>
It's not obvious to me whether you were planning to give off RGB or CMYK files. If you are giving the printer RGB files then it's all their problem. If you're giving them CMYK files the onus is on you to get it right. You are not getting a lot of help from their description; asking you to prepare a sep for between 12 and 18 percent dot gain is a lot like asking you to make a suit for somebody who is between five and seven feet tall.
>>If this was so, then if I do a conversion in Photoshop for a higher dot gain scenario, say, SWOP uncoated's 25%, then the photos would be much too light.>>
It would be, but you mention that they have two settings for dot gain. If you are choosing SWOP uncoated 25%, this suggests that your printing conditions are not all that hot. Nothing wrong with that, but the reason the printer has two settings is, the lower dot gain is to cater to people who have reasonably good printing conditions and the higher to people like yourself. The second setting won't look as pretty but it will be more accurate in predicting what will happen on press. So, you should be asking them to use their second setting on the proofer, assuming that you indeed are printing on uncoated paper.
In shops I've seen with two settings like this I'd start the guesswork by assuming 17% and 22%.
Dan Margulis
From: Dan Margulis, Date: Thu, Mar 23, 2000, 10:27 AM
RE: Re: dot gain and Matchprint
Bob Smith writes:>>Thats wonderful, but in my admittedly limited experience thats certainly not the norm. “Scared to death” may not be an appropriate description... “don't have a clue” might be better; but I otherwise agree with Cris's assesment.>>
Colorspace-centrism is bad no matter where it comes from, but you can't blame people for not being familiar with things of which they they have little experience. Print shops and service bureaus often do have trouble with RGB just as many photographers have trouble with CMYK just as I have trouble with extremely intricate merges of images. All of the above, however, would do very well for themselves by learning more about how the other half lives.
>>However the majority of those same shops will completly choke when given RGB input. I see this changing slowly.>>
I would amend that to say, they may completely choke when given RGB input *from a professional photographer.* Although photographers are a vocal group, they are a small minority of all those who might provide a print shop with an RGB file. The distinction is that when somebody like Les provides an RGB file it presumably is in good shape and the object should be to come fairly close to it in CMYK. However, that isn't the typical case; usually the shop couldn't care less whether it matches the RGB file because major corrections are necessary.
I see it changing, if at all, because of more familiarity with RGB output, not because of what clients are providing. Clearly photographers are more inclined now to bypass the whole issue by providing CMYK themselves. I see those quality-conscious people who insist on providing RGB and hoping for the best as a diminishing group.
>>I think all of this is driven by customers that want a variety of output and don't want to deal with several providers to get it.>>
I think so too; there's no doubt that clients want this. This is why it would behoove the service providers to learn more about RGB behavior. It would, however, behoove the photographer even more to learn CMYK, so that he won't be at the mercy of the service bureau and the printer.
Dan Margulis
From: INTERNET:dantel@rb-group.com,
Date: Thu, Mar 23, 2000, 1:29 PM
RE: Re: dot gain and Matchprint
Just to hitch hike on the tail end of this thread, the most irritating thing about all of this is the condescending tone in many of the voices when speaking of trade shops and printers - especially when referring to “old timers”. Well folks, do you refer to old carpenters or plumbers like that? These people are true craftsmen - I am not an old timer - but have been around long enough to meet many talented CMYK people - I'm one myself and only in my early 30's.My company has been working with color management for almost two years and have not found it to be a replacement for many of the tried and proven methods we employ - to suggest things like we are scared to death is just foolish and ignorant - it's no wonder the people who make these statements don't get along with printers - they probably don't get along with most people because of their arrogant know it all attitudes!
I have followed threads even recently by you guys who probably consider yourself the “gurus” of color management where it has become evident to me that some of you do not even understand some of the most basic film/digital proofing systems on the market - get with the program - high quality printing is not likely to be done on the likes of an Epson 5000 any time soon! If your printer or trade shop balks at what you give them then find another one - don't waste your time - you would not shop at a store that gave you lousy service for very long.
Dan Tesch
Director of Technology
R&D Group Chicago, IL
From: Bill & Mary Anne Stewart,
Date: Thu, Mar 23, 2000, 1:05 PM
RE: Re: dot gain and Matchprint
Amen! I have experienced the same frustration with the condescending tone and opinionated attitudes about color management in trade shops as well as within this discussion group. As shops like mine struggle with clients and vendors that are in many different stages of the “color management” issue, we are striving to learn what is necessary to survive in this changing world of print. In my shop, some of our jobs go to small trade shops that still output one- and two-color jobs from mechanicals - on the opposite end of the spectrum, we have sent out jobs (including a 176 page book) that were output from PDF files prepared by us. For our interstate billboard jobs (not offset, but still color issues), some go out as CMYK Scitex CT files, while others go out as RGB application files to be separated in RIP by the supplier (in this latter case, the suppliers seem to prefer the separations tables built in the machine rather than separating in PhotoShop or whatever). In our most recent annual report file, the cover outside was CMYK and the cover inside was duotone using black and one Pantone spot color. We ran it on a 6-color press on a “work and turn” - as there is no real way to proof spot colors or duotones, try color managing that one and proofing it to a digital! In all these cases, we are responsible to our clientele for the color, and we have made many efforts to be sure we can offer this kind of accuracy, and we use both film based and digital proofing as necessary. Some of our efforts to proof colors (and test our separations tables with a new printer) include old fashioned “Kentucky windage” - where we send a test file for printing and “screw up the monitor to fit the print.” This doesn't even begin to touch on the problems with trying to “match” the clients' jobs in website design or multimedia content, which we ALSO do.The point I am making (and have tried to make before, only to have my e-mail chopped up and selectively quoted and flamed by some) is that we are all in the same situation: trying to hit and ever-moving target called “accurate color proofs.” I have had good luck with machines like the Epson 5000, but I have also been burned. Film based proofing has its limitations, as everyone here knows, and it obviously doesn't work for spot colors or duotones - but it is at least a known and understood process with a long history and some measure of development stability (in other words, it isn't changing every day like digital). Digital proofing is changing even as we speak, which makes it even more difficult for shops with varied clientele to keep up. I envy those of you who have the leisure of working in a “closed loop” process where you have total control over original artwork, scanners, proofers, etc. - wish the rest of us could have the same luxury! I joined this list because I believe it is important to share with each other those things that HELP us to learn and HELP us to do a better job for our clientele - not tear each other down. Shops like me need the advise and expertise from those of you (and there are obviously many) who have had good luck and good experience with color management and digital proofing. There is no doubt of that. I just can't read or absorb views that I feel are biased and full of invective - I hold such opinons as suspect and not worth reading. Sorry!
Most of the folks on this list have been very helpful and supportive in my view, so please don't take offense if the proverbial shoe doesn't fit. Unfortunately, there is a small, though disproportionately vocal, minority that seems to enjoy pontificating and lecturing as opposed to helping. This is why I have chosen to paricipate but little on this list.
Thanks, Dan Tesch, for providing this feedback. I have received private e-mails from folks on this list expressing the same feelings as Dan has, but apparently they feel uncomfortable posting their thoughts on this matter. Frankly, I can see why as I am lining my machine with asbestos to safeguard against the napalm that will undoubtedly come my way from at least one quarter!
Bill Stewart
The Bayberry Design Co., LLC Salem, CT 06420 http://www.bayberrydesign.com Digital Graphic Design and Publishing Solutions for Print and the Internet
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 1:56 PM
RE: Re: dot gain and Matchprint
>Where do you see this CMYK world coming to an end?I said CMYK *only* world coming to an end; not CMYK (in its entirety) coming to an end.
>Are “contract quality proofs” now including RGB proofing systems?
Sure. In terms of color.
>We are not “scared to death” of RGB images. We know quite well what they
>are and the risks associated with accepting them. At my shop we are well
>informed on color management, we have the technology and we've evaluated
>the results under controlled systems.You are an exception, I never said every service provider was scared of them. By and large, most service bureaus are scared of them.
>>It's one thing to write articles and evangelize, totally another to stand in the viewing booth with the customer and discuss the print.>>
I do far, far, more of the latter than the former. I haven't written an article in almost a year.
cm
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 2:14 PM
RE: Re: dot gain and Matchprint
>I would amend that to say, they may completely choke when given RGB input *from a professional photographer.*>From anyone. A majority of service bureaus insist on receiving CMYK images, or they want to charge you for a scan. It's either or.
>I see it changing, if at all, because of more familiarity with RGB output, not because of what clients are providing.
I disagree. There is an increasing number of customers who have no idea how to get images into CMYK, let alone properly. They are submitting digital camera images, or they are doing their own scans. There are more of these people than there are true RGB devices being installed at prepress shops around the country. Actually I'm unaware of a single RGB output device at any of the prepress shops I frequent. Why would they?
> Clearly photographers are more inclined now to bypass the whole issue by providing CMYK themselves.
Of course, the “service” bureau won't do it for them. They have little choice.
> I see
>those quality-conscious people who insist on providing RGB and hoping for
>the best as a diminishing group.Only because of how difficult it is to find a service provider who is willing to accept RGB images not only without fuss but actually convert them properly.
>It would, however, behoove the photographer even more to learn CMYK, so that
>he won't be at the mercy of the service bureau and the printer.Sure, considering the circumstances I agree 100%; but it's a lost opportunity for the “service” bureaus.
chris murphy
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 2:28 PM
RE: Re: dot gain and Matchprint
>Just to hitch hike on the tail end of this thread, the most irritating thing about all of this is the condescending tone in many of the voices when speaking of trade shops and printers--especially when referring to “old timers”.I don't recall referring to anyone as an old timer, as a matter of fact I distinctly recall not using that term because I never use that term. You're interpreting a condescending tone that doesn't exist. If I didn't care about service bureaus then I'd only encourage other people to learn how to make separations and leave the service bureaus to rot, as eventually they will if they don't have any services to offer.
What primary services to prepress shops offer?
1.) Scans/separations
2.) File management (which includes a lot of other stuff - interfacing with printers, preflighting job, proofing, trapping, etc.)
#1 is going away. They are losing out on scans year after year and it's accelerating. People are scanning their own stuff with high end scanners suitable for the primary use of those images; and they are using digital cameras. The service bureau is losing the scan and separation business and eventually it will be gone.
#2 is diminishing as preflight tools do a better job, creative organizations add some prepress services, printers add the other needed prepress services, and service bureaus are being squeezed out. That's why so many of them are getting into other services like short run digital printing.
>My company has been working with color management for almost two years and >have not found it to be a replacement for many of the tried and proven >methods >we employ - to suggest things like we are scared to death is just foolish and >ignorant - it's no wonder the people who make these statements don't get >along >with printers - they probably don't get along with most people because of >their arrogant know it all attitudes!
I get along with printers and service bureaus just fine. Those who are open minded and realize the trends come to me and others like me to jump start usable color management so they can accept RGB images or CMYK images and not bat an eye at either one.
Speaking of scared to death, do you accept RGB images? Do you enjoy accepting RGB images? Far better to have more data, raw data, original data, respect the embedded profile to know what the customer is expecting (in a relative fashion), instead of converting haphazardly into CMYK not knowing a thing about the original (by the way, where is the original? there is no original with digital photography) and inadvertently introducing color casts or removing desired color casts. I hear the sound of redos. Who is in a better position to make the separation to CMYK? Someone who knows what they are doing with years of experience, or someone who's learn how to push buttons?
>I have followed threads even recently by you guys who probably consider yourself the “gurus” of color management where it has become evident to methat some of you do not even understand some of the most basic film/digital proofing systems on the market--get with the program--high quality printing is not likely to be done on the likes of an Epson 5000 any time soon!
Speaking of arrogant know it all attitudes, there is an ever increasing base of ad agengies using Epson 5000's properly color managed to generate color proofs more accurate (i.e. compared to what pops off the press) than they are getting from analog proofs. Printers and service bureaus are finding this as well and are astounded. While they don't get dots, they do get closer color simulation of the press a job will be printed on. They're are hundreds of installations all over the globe of people using even one niche product, Epson 5000's and Canon BJC 8500's driven by the BEST Color RIP. Others are using Di/Plot or BlackMagic, or SeeColor to generate proofs that surpass the predictability of analog proofs (sans dots) in terms of color.
They absolutely have their value, and any time soon happened about 18 months ago.
chris murphy
From: Andrew Rodney, INTERNET:andrew@digitaldog.net
Date: Thu, Mar 23, 2000, 2:35 PM
RE: Re: Dan-Re: dot gain and Matchprint
Dan Tesch wrote:> Just to hitch hike on the tail end of this thread, the most irritating thing about all of this is the condescending tone in many of the voices when speaking of trade shops and printers - especially when referring to “old timers”.
Technology doesn't change all that fast in the plumbing industry like it does with digital. The span of 4 or 5 years in computer imaging is probably equivalent to 30 years in those other trades.
I agree it's not a good idea to be condescending to this group although time after time experiences with such people make it hard not to think these thoughts. Just this week I spent two days at a very large printer in Texas (they do $20 million dollars a year in this one location). I was asked to come in and help them with their new, $100,000 digital photo studio. This studio and the people that run it (mostly photographers and designers) are across the street from the main “prepress” division. They must deal with RGB since this is the way the camera is going to spit out files.
Dealing with the prepress people and their attitudes was typical of experiences I've had over the years. The plant manager didn't even know how to answer a simple question I had when building an output profile to their Matchprint and Iris proofing systems (“what would you like for total ink limit?”). They are perfectly happy using Photoshop's “defaults” for CMYK conversions when they have to do RGB to CMYK mode changes (like for the stuff coming off the Leaf Volare camera in the new studio). No wonder their output looked so poor.
I profiled the Iris, the MatchPrint and the Volare. I provided them with a number of RGB images and asked them to output the files as they always do. I used the new ICC profiles and workflow and provided them with CMYK files to output as well. Under the light box, the difference was night and day. The owner of the company about fell over. The “old time” prepress people in the meeting were still highly suspicious and flat out told the owner that they were unable to use these new profiles “because we's have to change our settings etc...” At least the Photo Studio will be able to produce superb color output. We were able to lay down a Macbeth color checker shot in the studio next to our file converted to Iris and the match was so close it was scary. Their output was a mile off! The reluctance to even discuss a new, better way of converting color was obvious. This is hardly a rare experience for me! Their clients were not unhappy with the work they were providing so why change (Even if a new technique would improve the output drastically)? Their scanner (an Eversmart) was set to scan into sRGB! These guys didn't have a clue...Worse, they didn't want to even understand the processes they were committed to with the RGB devices they purchased! With that kind of attitude, I find it hard to respect people that are stuck in the old ways of doing and thinking even when clearly superior color output is a foot in front of them. They have to sleep at night with this realization of how much better and more accurate the color COULD be and do so while continuing to stick with their old techniques. I get to sleep at night knowing I can provide that color and that one division at this company will be producing vastly superior output with these new tools.
>> high quality printing is not likely to be done on the likes of an Epson 5000 any time soon!>>
Well define high quality printing and ask yourself who's suggesting an Epson 5000 is anything more than a very affordable and quite excellent proofer. It can, when set up properly, output proofs that are just as good and accurate as an Iris.
Andrew Rodney
www.digitaldog.net
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 2:53 PM
Re: dot gain and Matchprint
>>We ran it on a 6-color press on a “work and turn” - as there is no real way to proof spot colors or duotones, try color managing that one and proofing it to a digital!>>This is misleading. If the Named Color is reproducible in the gamut of the inkjet (and about 70% to 80% are depending on the inkset being used), and you are working with solid named colors, and not tints, then they can be proofed very accurately.
As soon as you introduce either an overprint with a Named Color, or a tint you introduce behavior that we don't have a way of predicting yet without taking a lot of measurements. You could make an NCP (Named Color Profile) which is a class of ICC profile, that contains a range of tints, and even overprints if you wish. It would be a lot of work and very expensive, but you could do it. So long as press behavior is consistent, and you use only that ink and that paper combination (otherwise tints will suffer from variable dot gain), the NCP is valid. But it's such a PITA that I don't know anyone who's done this for a press (I've done it for several inkjets to experiment with the possibility).
Anyway, given the limitations (if it's a solid, no overprint, and it can be reproduced on the inkjet in terms of gamut limitation), you can proof spot colors.
>This doesn't even begin to touch on the problems with trying to “match” the clients' jobs in website design or multimedia content, which we ALSO do.
This is not that difficult, I have customers that do this all the time. The best you can hope for is to have a good profile for the output conditions to be used, and convert all images from CMYK to sRGB, and post the sRGB images. Works very well, and can even be batched process to save time. Customers using it find it works better and faster than any other solution they've used thus far. If you ask I can tell you how to do this step by step.l
>I have had good luck with machines like the Epson 5000, but I have also been burned.
Absolutely. I would never suggest you be responsible for someone else's printing process or proofing process. At this point, it's safer for the printer to generate the proof, be it analog or digital because he is responsible for both the proofing process and the press. The customer shouldn't be responsible for his press, and the printer shouldn't be responsible for the customer's proofing device.
>>I joined this list because I believe it is important to share with each other those things that HELP us to learn and HELP us to do a better job for our clientele - not tear each other down.>>
I only said “scared to death” and that was facetious; I see the look on service bureaus faces when I say, “you need to learn to work in RGB also, you customer are going to demand it, and digital camera originals necessitate it.” Their eyes indicate they are going into shock or cardiac arrest, so I just coined it “scared to death.” I never said EVERYONE was like that.
If you want help then you need to stay open minded instead of being assured that color mangement doesn't work, or can't help in even the smallest degree, or certainly color managment “gurus” are ignorant and arrogant. That isn't about helping each other either, and I would also consider that overtly condescending compared to my Angsthase euphemism.
chris murphy
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 3:04 PM
RE: Re: Dan-Re: dot gain and Matchprint
>>With that kind of attitude, I find it hard to respect people that are stuck in the old ways of doing and thinking even when clearly superior color output is a foot in front of them.>>I'd like to add anecdotal evidence to slightly alter what I know Andrew is intending to say. Not that old skills are bad, but the status quo is bad. Things change, get used to it.
I know an “old timer” of the craft who is quite possibly the best CMYK color corrector in all of the South and definitely in Tennessee. With a group of prepress people, himself included, I spent 2.5 days “pontificating” about color management and how helpful it can be, as well as the importance of learning to work in RGB and using color mangement to HELP get those images into very nice starting point in CMYK because it will save a lot of time and effort. Day 3 he was one of the only people I recall asking a question about RGB settings and color correction methods that indicated he was not only FOLLOWING the recommendation but was TRYING it out himself. As I was packing up and leaving, I found him at his workstation, working in RGB and trying it out.
That is the definition of professionalism to me. Someone who is skilled at what they do and always ready to learn something new, and apply current skills to adapt to new realities. His skill set is likely to be valid until the end of time, but he has adapted how he uses his skill to take advantage of the situation.
It is simplistic to say “it doesn't work,” in lieu of how many people have gotten it to not only work but save them DAYS and hundreds of THOUSANDS of dollars in reduced redos and mistakes and less expensive interim proofs and fewer delays and cycles.
chris murphy
From: Bill & Mary Anne Stewart
Date: Thu, Mar 23, 2000, 3:25 PM
Re: dot gain and Matchprint
Chris quoted from my posting:
>>We ran it on a 6-color press on a “work and turn” - as there is no real way to proof spot colors or duotones, try color managing that one and proofing it to a digital!>>Chris wrote:
>>This is misleading. If the Named Color is reproducible in the gamut of the inkjet (and about 70% to 80% are depending on the inkset being used), and you are working with solid named colors, and not tints, then they can be proofed very accurately. As soon as you introduce either an overprint with a Named Color, or a tint you introduce behavior that we don't have a way of predicting yet without taking a lot of measurements. You could make an NCP (Named Color Profile) which is a class of ICC profile, that contains a range of tints, and even overprints if you wish. It would be a lot of work and very expensive, but you could do it. So long as press behavior is consistent, and you use only that ink and that paper combination (otherwise tints will suffer from variable dot gain), the NCP is valid. But it's such a PITA that I don't know anyone who's done this for a press (I've done it for several inkjets to experiment with the possibility). Anyway, given the limitations (if it's a solid, no overprint, and it can be reproduced on the inkjet in terms of gamut limitation), you can proof spot colors.>>My response:
This is an example of selectively quoting from a posting. Read my original carefully, please. “In our most recent annual report file, the cover outside was CMYK and the cover inside was duotone using black and one Pantone spot color.” is what I wrote. That is not the same thing as a Named Color. The print job called for CMYK on the outside of the front, and duotone using a SPOT color on the inside of the cover. In previous postings, you took my head off in front of the rest of the list over this very point, as you seemed to feel that I didn't know the difference between a SPOT color and its process equivalent. Here, you seem to make the same mistake you accused me of, and all because you evidently did not read the posting. The point I was making in the above reference is that jobs today are highly complex and sometimes there really is no one perfect way to proof: digital or analog. The skill and experience of the designers and prepress service people is what is important here as well as their ability to work together, and that is why we have lists such as this.Chris quoted from my posting:
>>This doesn't even begin to touch on the problems with trying to “match” the clients' jobs in website design or multimedia content, which we ALSO do.>>Chris responded:
>>This is not that difficult, I have customers that do this all the time. The best you can hope for is to have a good profile for the output conditions to be used, and convert all images from CMYK to sRGB, and post >the sRGB images. Works very well, and can even be batched process to save time. Customers using it find it works better and faster than any other solution they've used thus far. If you ask I can tell you how to do this step by step.>>My response:
Again, the point I make is only that jobs are getting more complex, and we do need each other--not inflammatory responses. I appreciate that you would be willing to help, and I may ask sometime--thank you. What I ask for now, though, is helpful postings from everyone, and not so much of the “I am right, and I told you so” attitude I have been experiencing.Chris quoted from my posting:
>>I have had good luck with machines like the Epson 5000, but I have also been burned.>>Chris responded:
Absolutely. I would never suggest you be responsible for someone else's printing process or proofing process. At this point, it's safer for the printer to generate the proof, be it analog or digital because he is responsible for both the proofing process and the press. The customer shouldn't be responsible for his press, and the printer shouldn't be responsible for the customer's proofing device.My response: I agree.
Chris quoted from my posting:
>>I joined this list because I believe it is important to share with each other those things that HELP us to learn and HELP us to do a better job for our clientele - not tear each other down.>>Chris responded:
>>I only said “scared to death” and that was facetious; I see the look on service bureaus faces when I say, “you need to learn to work in RGB also, your customers are going to demand it, and digital camera originals necessitate it.” Their eyes indicate they are going into shock or cardiac arrest, so I just coined it “scared to death.” I never said EVERYONE was like that. If you want help then you need to stay open minded instead of being assured that color mangement doesn't work, or can't help in even the smallest degree, or certainly color management “gurus” are ignorant and arrogant. That isn't about helping each other either, and I would also consider that overtly condescending compared to my Angsthase euphemism.>>My response:
Where do you get the idea that I or anyone else on this list is a) not open minded, b) thinks color management does not work or cannot help, and c) of the opinion that color management “gurus” are ignorant or arrogant?As for A) you only need to read more carefully my postings. My company works in RGB as well as CMYK, we deal with digital files for print and the internet, and we are definitely open minded about color management--it is a fact of life with which we all must contend, but it is not without its flaws. I do not embrace color management completely the way some others do for the simple reason that I am approaching things very cautiously with the different clientele needs with which I must deal. As for B), I do know that color management can work, especially in a closed loop environment. I have seen it first hand, but I have not had the luxury of such experience myself. As for C), I am guessing you got e-mails mixed up as I never made any disparaging remarks about color management “gurus”. Again, if you read and quote correctly from my original posting: “Shops like me need the advise and expertise from those of you (and there are obviously many) who have had good luck and good experience with color management and digital proofing. There is no doubt of that.” How can you possibly think of that as disparaging towards you?
I appreciate your experience with color management and the like. Believe it or not, I do get a lot of info from your postings as you seem to be one person on the list who has much experience in this area. You do, however, have a propensity for quoting sections of my postings out of context, and I consider that to be rather bad manners. Please read my postings carefully as I do put them together with some amount of care. If you read them carefully, you will find that I am (like many on this list) open and willing to learn and develop the skills needed to operate in a digital-proofing world as that is where the future lies. I tend to view with suspicion opinions that sound like the writer is so biased as to view his/her way as the only correct way and treat all other views with hostility.
Bill Stewart
The Bayberry Design Co., LLC
20 Hartford Road, Suite 32 Salem, CT 06420
stewart@bayberrydesign.com
http://www.bayberrydesign.com Digital Graphic Design and Publishing Solutions for Print and the Internet
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 5:29 PM
RE: Re: dot gain and Matchprint
>>Possibly, but you should know that just today I have had e-mails from a number of folks on the list expressing thoughts similar to mine. I am not getting into a “he said - he said” however >>I think that started happening four or five emails ago, and I am equally guilty through attempts to clarify. Anyone is more than welcome to respond to me offline if they feel they're going to get publically flogged and flamed or whatever. I'm not meaning to be insensitive to those who might feel that way, but it's absolutely not my style to flame. Flaming in my mind is name calling, accusatory and by nature doesn't get to the point.
Pulling apart what someone has said, disagreeing with it (even strongly), and pointing out why there is disagreement is definitely not flaming. I have been an original internet participant before it was called the internet. I *KNOW* what flaming is, as I've been involved in a number of them in the past (i.e. me being royally flamed, then me flaming back). So now in addition to how off topic this has become we can now agree to disagree on the definition of flaming.
>>A second issue: what is the general take out there on color copiers for print?>>
Well if you don't mind an inconsistent product, then they're fast and generally pretty decent. I've had mixed results profiling them. A single day/time profile is almost worthless, but you can generate an “average” profile to describe/predict average behavior. This way you are neither right ON target nor way off from it. The technology is getting better however, and I would essentiall lump color laser and color copier as the same technology. We need to improve the technology with some means of autocalibration which right now is pretty limited.
For the short run stuff, you might even look at some of the heavy duty color lasers that are competing with color copiers. If you don't have a need to slap on an original onto glass and copy it, then a color laser might fit the bill better.
>>What are the feelings about RIP's with the Epson 5000? Anybody really like the Fiery with it? How about aftermarket RIP's?>>
At this point I'm prefering BESTColor's RIP although it would be nice if they could get multiple printer support so it would be possible to drive two 5000's (or three 5000's) from the same RIP; currently you need a separate NT box to run a second printer. Otherwise it's fantastic, fast RIP time, very nice. Currently I'm recommending the Canon BJC 8500 over the 5000. About the same price, more versatile (can proof on newsprint stock!) paper handling, more appropriate inkset for proofing process printing, higher resolution, faster, etc.
>>Some have posted their experience with certain third party RIP's, and I understand there is a Harlequin RIP as well - any experience with the Harlequin one on the Epson 5000?>>
Certainly if you already have a Harlequin RIP, getting the plug-ins needed to drive an Epson is a great way to go to get ROOM (RIP Once Output Many) and have a proof that has gone through you actual RIP used for imagesetting or platesetting. I like this idea a lot.
At least on the CTPP (Computer to Plate Pressroom, www.ctpp.com) list, this is a discussion going on right now.
chris murphy
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 4:11 PM
RE: Re: dot gain and Matchprint
>>This is an example of selectively quoting from a posting. Read my original carefully, please.>You made a distinction between spot colors and duotones. I didn't bring up your example of CMYK on the outside and duotone black + Pantone because it doesn't meet the requirements I've already mentioned. A duotone will necessitate both tints and usually overprints. That is not something easily color managed.
I was very specific to say proofing solid Named Color is something that can be done (within the limits of the proofer) very well and without much difficulty. This is why I referred to the above statement as misleading because it states in part “there is no real way to proof spot colors”. That part isn't entirely true. The second part “or duotones” is essentially true. That's why I used the term misleading instead of false.
>>“In our most recent annual report file, the cover outside was CMYK and the cover inside was duotone using black and one Pantone spot color.” is what I wrote. That is not the same thing as a Named Color.>>
Pantone, FocolTone, TruMatch - all of those are Named Color systems. If your duotone specifies a Pantone spot color, then it is using Named Color.
>>The point I was making in the above reference is that jobs today >are highly complex and sometimes there really is no one perfect way to proof: digital or analog.>>
That is a perfectly valid statement and is different in form and meaning than the first one which implies neither spot colors nor duotones can be proofed digitally via color management. While not false, it is misleading because it is possible to proof some spot color applications very well.
>>What I ask for now, though, is helpful postings from everyone, and not so much of the ”I am right, and I told you so” attitude I have been experiencing.>>
You are arriving at an event that isn't happening. I know what I wrote and what I intended, and this isn't it. I've “been there, done that” quite a bit and I've learned what works well and what works well but takes longer, and what doesn't work well. Either pick my brain or don't, but please don't tell me what my attitude is at least until you've met me in person.
>Where do you get the idea that I or anyone else on this list is a) not open minded, b) thinks color management does not work or cannot help, and c) of the opinion that color management “gurus” are ignorant or arrogant?
I am not going to name names; most of this was said today, but I've heard the rhetoric over and over again as well.
a & b) through inference upon hearing statements such as, “we couldn't get it to work,” or “we don't accept RGB, we only accept CMYK, it's safer.”
>>high quality printing is not likely to be done on the likes of an Epson 5000 any time soon!>>
c.) >>they probably don't get along with most people because of their arrogant know it all attitudes!>>
and
>>you guys who probably consider yourself the “gurus” of color management where it has become evident to me that some of you do not even understand some of the most basic film/digital >proofing systems on the market>>
>>I am guessing you got e-mails mixed up as I never made any disparaging remarks about color management “gurus”.>>
I'm not saying YOU (singular did), I'm speaking generically and not naming names. The owner of the statements above knows who they are.
The plea was for help and a complaint about the condescending attitude, yet within the complaint of arrogance and condescending attitude was arrogance and condescending attitude.
>>I tend to view with suspicion opinions that sound like the writer is so biased as to view his/her way as the only correct way and treat all other views with hostility.>>
We've had this discussion before. Your reading style and my writing style conflict. You're reading way too much emotion into the text I write. These events you're speaking of are not occuring and I think by default I'm in a better position to make a claim as to my state of mind, intention and my emotional involvement in the discussion.
Shall we talk about color now?
chris murphy
From: Bill & Mary Anne Stewart, INTERNET:stewart@bayberrydesign.com
Date: Thu, Mar 23, 2000, 4:45 PM
Re: dot gain and Matchprint
Chris wrote:
>>These events you're speaking of are not occuring and I think by default I'm in a better position to make a claim as to my state of mind, intention and my emotional involvement in the discussion.>>I respond:
Possibly, but you should know that just today I have had e-mails from a number of folks on the list expressing thoughts similar to mine. I am not getting into a “he said - he said” however - so I will leave it up to them to contact you separately. I will reiterate, however, that you have taken comments of mine out of context in postings and flamed me, which is clearly not a case of you knowing your “state of mind” better than me. There are better ways to disagree with someone. Please do not do that anymore, and I am sure we can get along. Unless someone other than me prolongs this, I intend to drop it and forget it.Chris wrote:
>>Shall we talk about color now? >>I respond:
I was wondering when we would get back to that! I would love to talk color, especially for accurately proofing duotones for colors. In the midst of all these postings today, several folks wrote privately to me to express their feelings about the tone of postings, and in their letters they also wrote some good stuff about proofing duotones. As for their feelings on the tone of messages, I will let them post and speak for themselves. As for duotones: one person mentioned a new system by Dupont called (I think) “CV”. Any feedback? I soft proof duotones for my clients, as I have been able to do that most successfully, but it would be great to be able to show them a printed piece. We have the Pantone Duotone chips, which help the clients view the specific duotone curve on a sample photo, but it would be helpful to show their own files to them in print.A second issue: what is the general take out there on color copiers for print? I am talking about 11” by 17” or even 12” by 19” color copiers purchased by and used by small copy shops, town government agencies, and similar. One client of ours likes to us to use our Annual Report design for them as a template for things like their Budget Report and other publications that only get 100-400 copies. They want to output them on a color copier, and I would like to make some logical recommendations. Everyone on this list knows that a color copier isn't going to output a file that necessarily looks like a printed piece, and the Annual Report is printed on offset press. I would like to be able to recommend to them a good machine for this.
Last question: The Epson 5000. In spite of all the negative feedback about it (some of which came from me), I know that some out there have had excellent luck with it. What are the feelings about RIP's with the Epson 5000? Anybody really like the Fiery with it? How about aftermarket RIP's? Some have posted their experience with certain third party RIP's, and I understand there is a Harlequin RIP as well - any experience with the Harlequin one on the Epson 5000? Is there a general feeling as to which RIP (if any) has had the best track record so far? There is no question that there is a need for a good digital proofer, and the Epson is certainly much cheaper than an Iris.
Thanks,
Bill and Mary Anne Stewart
The Bayberry Design Co., LLC
20 Hartford Road, Suite 32 Salem, CT 06420 stewart@bayberrydesign.com http://www.bayberrydesign.com
Digital Graphic Design and Publishing Solutions for Print and the Internet
From: Chris Murphy, INTERNET:lists@colorremedies.com
Date: Thu, Mar 23, 2000, 5:46 PM
RE: Re: dot gain and Matchprint
> >How accurate can the 8500 be calibrated?>>Technically calibration of both the Canon BJC 8500 and the Epson 5000 is limited to ensuring there is ink and paper in the device; you can modify calibration two ways; changing paper/ink, and changing driver settings (which will affect the droplet sizes and amoung of ink layed down on the paper).
As far as how accurate it can simulate a printing press, it is able to simulate at least as accurate as an Epson 5000 and in yellows it does a better job.
> Does it run off a separate RIP, or does it have it's own proprietary RIP? >>
It is driven from an external RIP, and I'm only aware of the BESTColor RIP at this point. I don't believe Canon has Mac QuickDraw drivers for it.
chris murphy
From: Bill & Mary Anne Stewart, INTERNET:stewart@bayberrydesign.com
Date: Thu, Mar 23, 2000, 5:38 PM
RE: Re: dot gain and Matchprint
Thanks. This kind of advice I appreciate.Bill Stewart The Bayberry Design Co., LLC 20 Hartford Road, Suite 32 Salem, CT 06420 stewart@bayberrydesign.com http://www.bayberrydesign.com Digital Graphic Design and Publishing Solutions for Print and the Internet
From: “Gene Morgan”, INTERNET:pixel@compu-type.net
Date: Thu, Mar 23, 2000, 7:12 PM
RE: Re: dot gain and Matchprint
The Canon BCJ 8500 and the HP DesignJet GA is available with the Imation(3M) Matchproof system RIP which does a fantastic job with 3m substrates.
From: John Sweeney
RE: Re: dot gain and Matchprint
Chris Murphy writes:> >yeah so don't use SWOP uncoated 25% dot gain to make your separations. >>
What is SWOP uncoated 25% ?
SWOP specs are for #5, groundwood coated, publicaton ONLY.
Where do these SWOP variants come from ?
John Sweeney Graphics Microsystems, Inc. (and SWOP advocate)
From: John Sweeney
Date: Sun, Mar 26, 2000, 8:11 PM
RE: Re: dot gain and Matchprint
Chris Murphy writes:> >Following SWOP, then not following SWOP in regards to paper and dot gain, making it NOT SWOP; but easier to write.
Fair enough--the good news is after 25 years SWOP is well recognized.
GRACoL 4.0 will be out with the May Graphic Arts Monthly, and those printing guidelines do a great job listing print characteristics for various grades of paper.
Let's hear it for SNAP, GRACoL and SWOP ! New SNAP (Spec for non-heatset printing) rev. is now, or soon to be, released.
John “Print by the Numbers” Sweeney
From: Chris Murphy,
Date: Sun, Mar 26, 2000, 7:23 PM
RE: Re: dot gain and Matchprint
>What is SWOP uncoated 25% ?Following SWOP, then not following SWOP in regards to paper and dot gain, making it NOT SWOP; but easier to write.
> >SWOP specs are for #5, groundwood coated, publicaton ONLY. > >Where do these SWOP variants come from ?
Printers. Prepress. Adobe. Other vendors. In about that order of freqency.
Chris Murphy
From: Chris Murphy
Date: Sun, Mar 26, 2000, 11:38 PM
RE: Re: dot gain and Matchprint
>Let's hear it for SNAP, GRACoL and SWOP !
>New SNAP (Spec for non-heatset printing) rev. is now, or soon to be, >released.Let's not forget PROP, FIRST, and ISO 12647! Prepress Requirements for Offset Packaging, Flexograpic Image Reproduction Specifications & Tolerances, and the International Standards Organization hopeful intended international “replacement” for GRACoL, SWOP, and SNAP and their foreign equivalents (so everyone is on the same page globally). It may be that SWOP, SNAP and GRACoL will incorporate ISO 12647 into their OWN specifications/requirements in lieu of actual replacement. Maybe John has more info on this?
Chris Murphy
From: John Sweeney
Date: Mon, Mar 27, 2000, 8:12 AM
RE: Re: dot gain and Matchprint
Chris Murphy writes:> >It may be that SWOP, SNAP and GRACoL will incorporate ISO 12647 into their OWN specifications/requirements in lieu of actual replacement. Maybe John has more info on this?>>
Absolutely !
ISO and ANSI CGATS Standards are what give Specifications, like FIRST, SNAP, GRACoL, and SWOP teeth. (or for that matter, any internal or company specs you develop).
Standards are the foundation of spec's, and there are of course many of us involved in both activites.
Spec's are no good without standards as a foundation. Standards are no good if nobody uses them Ñ that is the role of spec's, in my mind, organizing and reference standards in a way that makes them useful !
For example, before Status-T, we couldn't talk density numbers with confidence, outside a closed environment. (Same instrument manufacturer) Now when we talk about TVI (Tone Value Increase) AKA Dot Gain, etc. we all know how the measurement is to be made, the calculation, and how data is to be reported, AND we use these values with confidence.
In fact, I reach for SWOP 8'th edition when I need a quick list of standards.
The NPES “blue book” listing of all standards is great (free on request, www.npes.org) but I usually don;t carry one.
John Sweeney
SWOP - Don't leave home without it !
From: Dan Margulis
Date: Mon, Apr 23, 2001, 10:12 AM
RE: [colortheory] Inky fingers
--------------- Forwarded Message ---------------
To: Dan Margulis, 76270,1033
Date: Sun, Apr 22, 2001, 5:42 AMRE: Inky fingers
Dear Dan,
I really appreciated your Photoshop 6 guide. I'm a trained master
printer but have been working my way back through the print process for 15
years so now I also work as a print designer. I respect the fact that you
have worked in a trade house and that's why I'd like to ask you one very
tricky question.One particular 4 colour newsletter I design looks great on the matchprint,
just a bit too light but once on the press it should sparkle if you know
what I mean. Anyhow I went out to do a press check and noticed that the
printers were doing the job on a two colour with two passes.Naturally the finished job looked very ink heavy. Being a pressman I know
that you get the crispest result when you run a 4 colour job wet with one
pass. The inks are designed to be printed wet on wet, ink tack comes into
play, paper stretch while the job is sitting etc etc. My question is: "Is a
job printed in this manner going to have a higher dot gain setting
requirement in Photoshop?" I currently use 22% for a coated 150gsm recycled
monza art. Am I being paranoid or could this be the problem?Any info or feedback would be much appreciated as this one really has me
stumped.Many thanks,
From: Dan Margulis
Date: Mon, Apr 23, 2001, 4:38 PM
RE: [colortheory] Inky fingers
>>I went out to do a press check and noticed that the printers were doing
the job on a two colour with two passes. Naturally the finished job looked
very ink heavy. Being a pressman I know that you get the crispest result
when you run a 4 colour job wet with one pass. The inks are designed to be
printed wet on wet, ink tack comes into play, paper stretch while the job
is sitting etc etc. My question is: "Is a
job printed in this manner going to have a higher dot gain setting
requirement in Photoshop?" >>I agree that a job printed in two passes of 2/c each is likely to look different than running it as one pass of 4/c, even on the same press. However, I don't know of a technical reason why there would be necessarily more dot gain.
What's more likely is that the printer's customary practices on a 2/c press might have that tendency. In 2/c one is printing lots of solid colors and the temptation may be to set up blanket pressure and whatnot to favor heavier printing, since that would make most 2/c jobs look "better".
The bottom line is that any time one uses an unfamiliar output process one has to be prepared to adjust the dot gain compensation. Often one can make shrewd guesses in advance (computer-to-plate is very likely to have less dot gain than a negative-film workflow, for example) but that doesn't appear to be the case here.
So, if the job is printing too dark at present, yes, you should adjust the dot gain setting upward if you use this particular printer again.
Dan Margulis
From: Chris Murphy, lists@colorremedies.com
Date: Mon, Apr 23, 2001, 11:20 AM
RE: Re: [colortheory] Inky fingers
>One particular 4 colour newsletter I design looks great on the matchprint,
>just a bit too light but once on the press it should sparkle if you know
>what I mean.>Naturally the finished job looked very ink heavy.
What concerns me is the printing company shouldn't be accepting this particular Matchprint if their press won't match it. The printer can work with their ink vendor, to some degree, to deal with dry down and ink tack issues when printing four colors on a two color press, necessitating two passes. They should be able to get within a reasonable, mostly acceptable range of matching the Matchprint - assuming it's a suitable Matchprint. (There are something like 34 different Matchprints if you combine all of their possible bases and laminates.)
To me it sounds like a process control issue. And if they either can't improve on process control, or improvement still doesn't result in appropriate matches to the proof, then they need to refuse accepting Matchprints as contract proofs. And that goes with any proofing system. The whole point of the contract proofing method is not "well, we'll try to match your contract proof - but if we don't you still have to pay us 100% of the quoted amount." I don't think so. The contract proof has a very specific purpose and while exact reproduction is expected only by those who don't understand the nature of presses and analog proofs, they should be reasonable. Printing "very ink heavy" doesn't sound at all reasonable to me.
Did you suggest at all that you might reject this job, or at least future jobs if they can't be made to look better than this? If the printer is allowed to get away with this kind of "match" as acceptable, then they will try to get away with it and move on to the next paying customer. (That is logical afterall.) So I'd ask them what the story is here.
>My question is: "Is a
>job printed in this manner going to have a higher dot gain setting
>requirement in Photoshop?" I currently use 22% for a coated 150gsm recycled
>monza art. Am I being paranoid or could this be the problem?You can certainly make separation modifications in order to get what you want on press. That's how it should be done. The problem though is that now your Matchprints will come out *really * light, and the press will print a lot heavier than the proof. So while your final prints may come out OK, you still don't have a solution to the lack of continuity between press and proof.
I see the lack of press and proof continuity as the biggest problem.
Chris Murphy
Color Remedies (tm)
Boulder, CO
303-415-9932
From: Preston Earle
Date: Mon, Apr 23, 2001, 5:47 PM
RE: RE: [colortheory] Inky fingers
Dan forwarded the following edited message:> I'm a trained master printer . . .
> I went out to do a press check and noticed that the
> printers were doing the job on a two colour with two passes.> Naturally the finished job looked very ink heavy. Being a pressman I know
> that you get the crispest result when you run a 4 colour job wet with one
> pass. The inks are designed to be printed wet on wet, ink tack comes into
> play, paper stretch while the job is sitting etc etc. My question is: "Is a
> job printed in this manner going to have a higher dot gain setting
> requirement in Photoshop?"I am not a trained master printer, but I did spend last night in a Holiday Inn Express. (That is a US-centric joke.)
I would disagree that one-pass four-color printing is inherently crisper than two-pass or four-pass printing. One-pass printing has the weakness of having to deal with ink-trap issues that are less in two-pass and non-existent in four-pass work. Printing two-colors at a time makes color balance much more difficult than one-pass printing. I think it is incorrect to think that "Naturally the finished job looked very ink heavy." Could the printer have printed incorrect ink densities on the first pass and had to do something on the second pass to bring the color back into balance?
I'd suspect some press-related problem like incorrect densities. incorrect packing, or poor ink-water balance for the heavy ink look, rather than incorrect dot-gain in the film/plates. Did the form have color-bars and related targets to judge the other print conditions?
I hope this doesn't sound condescending and isn't a blinding flash of the obvious. I do know how difficult it is to diagnose press related problems without proper color-bars and test targets.
Preston Earle
PEarle@GPConline.com
From: INTERNET:LeeGrap401@aol.com, INTERNET:LeeGrap401@aol.com
Date: Sun, Jan 9, 2000, 2:26 PM
RE: dot gain settings
In Photoshop 5.0, if I change the dot gain % in the CMYK Color Settings, will this change show only on the screen as a visual idea of what the print will look like? Or will it actually change the separation output dot size, i.e. on film, to compensate for the % of dot gain on press that I have entered in the settings?Lee Collins
From: Andrew Rodney
Date: Sun, Jan 9, 2000, 2:35 PM
RE: Re: dot gain settings
Lee Collins wrote:
>>In Photoshop 5.0, if I change the dot gain % in the CMYK Color Settings, will this change show only on the screen as a visual idea of what the print will look like? Or will it actually change the separation output dot size, i.e. on film, to compensate for the % of dot gain on press that I have entered in the settings?>>
Both assuming you are dealing with an RGB file. If it's already in CMYK, the file isn't going to be altered but the preview will.
Andrew Rodney
From: Dan Margulis,
Date: Sun, Jan 9, 2000, 4:31 PM
RE: dot gain settings
Lee Collins writes:>>In Photoshop 5.0, if I change the dot gain % in the CMYK Color Settings, will this change show only on the screen as a visual idea of what the print will look like? Or will it actually change the separation output dot size, i.e. on film, to compensate for the % of dot gain on press that I have entered in the settings?>>
For a file that is in RGB now and forever, changing the dot gain setting has no impact. For a file that is already in CMYK, changing the setting affects screen display but not the printed result. For a file that is now in RGB but you intend to convert it to CMYK, changing dot gain setting will give you a different separation.
A more extended discussion of this took place a while ago when someone asked whether the advice his printer was giving him about dot gain settings was correct. I repeat my answer below.
Dan Margulis
>>1) Is the printer correct that my dot gain settings have no affect since they apply their own?>>
If you are supplying them RGB files, the printer is correct. The settings only have an impact on printing at the moment of separation. If you are supplying the printer RGB, that moment takes place at some point in the future and the printer is responsible. If you are supplying CMYK, that moment took place in the past, and your printer's advice is incorrect.
>>2) Is dot gain to make images look correct on screen or to make them print properly? I always thought it was for the latter but the article seems to imply both.>>
When you are in RGB, which has no inks and therefore no dot gain, the dot gain setting is an effort to make the separation print properly, when you finally make the separation. Once you are in CMYK, the only function is to make the screen look correct.
Example: you have dot gain set at 20%, but as it happens it should really be at 30%. Three workflows:
1) You convert the RGB file at 20%. The resulting CMYK now looks like the RGB file. However, it will print too dark.
2) You convert the RGB file at 20%, and then change the dot gain setting to 30%. Now the CMYK looks darker than the RGB, accurately reflecting that this is the way the job will print.
3) You change the dot gain to 30% before converting. The CMYK file now looks like the RGB, *and* it prints correctly.
4) you change the dot gain to 30% before converting, but back to 20% afterward for some reason. The CMYK file now looks lighter than the RGB, but this is a lie, as it will print correctly.
From: Lee Varis, INTERNET:varis@varis.com
Date: Mon, Jan 10, 2000, 8:24 PM
RE: Re: dot gain settings
Just coming out of lurking mode with a problem that's been troubling me for some time now:
Over years of being displeased with Photoshops separations I got used to using other applications for this purpose starting with ColorStudio and ending with Live Picture. Adobe published a white paper with Photoshop 3.0 that described a rather convoluted process for capturing other look up tables for use in Photoshop involving the Lab Colors file and CMYK Colors file (still found in the calibration folder in PS 5.5) I have been using a table captured from a tweaked Live Picture CLUT very sucessfully for the last few years and starting with PS 5.0 when this table is saved from the tables dialog box the result is an ICC Profile. I would like to start using this profile with clients that insist on embedded profiles ( you may laugh but I do actually have one client that is demanding profiles) You can find a fairly detailed description of this procedure on my web site at:
http://www.varis.com/Technique/CustomSepTables/CustomSeparations.html
if you're interested in Live Picture be sure and dig a bit further to find the even more convoluted steps necessary to generate a sucessfull PS table from LP.
Now the problem is that no matter what I do I can not get Photoshop to generate identical results to images separated directly in Live Picture even when I use essentially the same table. This is especially irksome in colors that approach the purer ink primaries, yellow, magenta, cyan, ect.. Using Live Picture I have no trouble getting an RGB value of 255R,255G, 0B to yield a great yellow of 100%Y, 0%C, 0%M, 0%K. I know you'll all say that there are no colors in the real world that pure, but I must tell you that I've photographed rainbow gradient reflections from gold CD discs that have these kind of colors and sometimes illustrated elements in photo-composites would look a lot better if I could maintain a little better color purity in the separation. Also LP tends to produce smoother gradients with less noise, especially neutral gray ramps. Now, with Live Picture being the Orphaned application that it is and Colorsync workflows becoming more popular, it would be convenient to make it all work in Photoshop at least better than it does now. Some of the Live Picture software engineers have told me that LPs superior separations are the result of the calculations being carried out in a 48bit colorspace, smaller round off errors and all that but I was under the impression that Adobe's Colorsync CMM worked in 16bits per channel as well. I still get dirtier colors when separating in PS with the LP table. Is their some way to tweak the table so that I can get a bit more color gamut out of it - I've tried editing the Lab Color separated file in PS before re-saving it as a table but I just seem to get in trouble in some other area of color. Any ideas?
Best Regards,
-Lee Varis
voice: (323) 937-3793
fax: (323) 937-3795
e-mail: varis@varis.com
web: http://www.varis.com
From: Andrew Rodney,
Date: Mon, Jan 10, 2000, 8:39 PM
RE: Re: dot gain settings
Lee Varis wrote:> Now the problem is that no matter what I do I can not get Photoshop to > generate identical results to images separated directly in Live Picture even > when I use essentially the same table.
Well remember that PS5 uses RGB Working Spaces as a source for the transform. So the question is, what does LB do and can you match that (if it's using a display profile as a source, this may not be a good idea). You'll also have to mess with rendering intents and figure out just how LPoperated with respect to CMM's. It may not be possible to get the two to produce identical results but you should get close depending on what and how LP dealt with ICC profiles.
> Now, with Live Picture being the Orphaned
I heard that it was picked up by MGI.
> Some of the Live Picture software engineers have told me that LPs superior > separations are the result of the calculations being carried out in a 48bit > colorspace, smaller round off errors and all that but I was under the > impression that Adobe's Colorsync CMM worked in 16bits per channel as well.
Ya, it does so I'd take what the LP engineers say with a grain of salt. Now while the actual transforms do take place in high bit, and you should use Profile to Profile to get 100% of ColorSync for the transformation, LP most likely always worked on high bit files (rather than converting 8 bit to higher bit for the conversion). So for those smooth gradients, you'll want to stick with high bit scans and keep em that way until you do the conversion in Profile to Profile. Your editing will be limited though (no layers unlike LP). Once you convert to CMYK you can go back to 8 bits and use all the goodies PS provides. Let's hope that PS6 has FULL 16 bit support for all tools!
> Is their some way to tweak the table so that I can get a bit more color gamut > out of it
A good profile editor will allow you to tweak saturation. But if the profile is at the edge of the gamut already, that's not going to help.
Andrew Rodney
From: Dan Margulis
Date: Tue, Jan 11, 2000, 4:25 PM
RE: Re: dot gain settings
Lee Varis writes:>>Now the problem is that no matter what I do I can not get Photoshop to generate identical results to images separated directly in Live Picture even when I use essentially the same table.>>
It's conceivable that you may have to get yourself a profile editor and horse around a little if you are looking for a really close match. Otherwise, you'll have to figure out how LP defines RGB. If you can make PS's RGB match up with LP's, that should make the table work.
>> This is especially irksome in colors that approach the purer ink primaries, yellow, magenta, cyan, ect.. Using Live Picture I have no trouble getting an RGB value of 255R,255G, 0B to yield a great yellow of 100%Y, 0%C, 0%M, 0%K.>>
This is because in most of Photoshop's built-in RGBs 100Y is out of gamut (as it is in most RGBs; CMYK's yellow is very intense). Therefore, there isn't any way of getting a yellow that intense, unless you change your RGB to Adobe RGB, which *does* have the capability, or unless you make other arrangements to restore the color later.
>>I still get dirtier colors when separating in PS with the LP table. Is their some way to tweak the table so that I can get a bit more color gamut out of it - I've tried editing the Lab Color separated file in PS before re-saving it as a table but I just seem to get in trouble in some other area of color. Any ideas?>>
Four possibilities, pretty much mutually exclusive.
1) Change RGB Setup to Adobe RGB, but be aware that this may cause other color problems.
2) Don't change the RGB, but write a conversion Action that takes the file into LAB, and applies a curve that steepens the B channel (and the A as well, if you are also having trouble with reds), then converts to CMYK using your table. This also may cause other problems but it probably will give a little more fidelity to the original intent than will changing the RGB definition.
3) Generate a new table using the Lab Color file, except while the file is still in LAB pivot the B curve counterclockwise. This is very, very, ugly, but it probably will work after a fashion.
4) Do everything the way you're currently doing it, except once in CMYK, have an Action that will Image: Adjust>Selective Color by adding yellow to yellows (and intensitying also whatever colors you may be having problems with.) This is probably the least faithful to the original RGB, but it may also be what you want, since it will really make the bright colors pop.
Dan Margulis
From: Lee Varis
Date: Tue, Jan 11, 2000, 10:27 PM
RE: Re: dot gain-should have been tables problems
Thanks Dan,I've been using #4 for a while now minus the action (just manual tweaking):
>4) Do everything the way you're currently doing it, except once in CMYK,
>have an Action that will Image: Adjust>Selective Color by adding yellow to
>yellows (and intensitying also whatever colors you may be having problems
>with.)I'm going to give those LAB moves a try though, thanks for the suggestion!
As for suggestion #1
>>1) Change RGB Setup to Adobe RGB, but be aware that this may cause other color problems.
When I use Adobe RGB the other color problems are that tones near to highly saturated ones get crunched towards and collapse into the saturated ones so that I end up with tones that should render with a 10% difference being the same thus flattening regions where there should be tonal variation. This is very, very bad because then I have no remedial fix with curves, etc. and I still don't get absolutely pure saturated colors.
Best Regards,
-Lee Varis
voice: (323) 937-3793
fax: (323) 937-3795
e-mail: varis@varis.com
web: http://www.varis.com
From: Chris Murphy,
Date: Wed, Jan 12, 2000, 12:37 AM
RE: Re: dot gain-should have been tables problems
>When I use Adobe RGB the other color problems are that tones near to >highly saturated ones get crunched towards and collapse into the >saturated ones so that I end up with tones that should render with a 10% >difference being the same thus flattening regions where there should be >tonal variation. This is very, very bad because then I have no remedial >fix with curves, ect.. and I still don't get absolutely pure saturated >colors.This is because Adobe RGB, generally speaking, has a larger gamut than the process printing gamut. In order to maintain distinctive tonal variations, you must use some form of gamut compression when converting from source color spaces that are larger than the destination. More accurately, one should use some form of gamut compression during the conversion to CMYK when the source IMAGE (not the source space) contains colors that are out of gamut for the output device to be used, and you care about maintain detail/distinction in those areas.
The built-in tables in Adobe Photoshop use a very small amount of gamut compression. Colors that are in-gamut must be brought further in-gamut (desaturated) in order to make room for those on the gamut boundary. The only way you can take advantage of larger amounts of gamut compression is to use an ICC profile in Photoshop 5, and specify the perceptual rendering intent.
Chris Murphy
From: Dan Margulis,
Date: Wed, Jan 12, 2000, 12:09 AM
RE: Re: dot gain-should have been tables problems
Lee Varis writes:>>When I use Adobe RGB the other color problems are that tones near to highly saturated ones get crunched towards and collapse into the saturated ones so that I end up with tones that should render with a 10% difference being the same thus flattening regions where there should be tonal variation. This is very, very bad because then I have no remedial fix with curves, ect.. and I still don't get absolutely pure saturated colors.>>
This harks back to a recent thread on this list. There are indeed a lot of advantages to working with Adobe RGB--pleasing, vivid colors primarily. There is also a flip side, described accurately above by Lee. Those who are knowledgeable about color correction need to ask themselves whether it makes more sense to work with a smaller-gamut RGB, which will often require the use of curves for correction, or Adobe RGB, where you have to be a channel-blending maven to get acceptable results.
Dan Margulis
We are doing a book cover that features an intricate pattern drawn in Illustrator, exported as an EPS and then placed in quark for seperations and film. If this were a tiff, I would know how to set cmyk settings for dot gain on the press we are running on but since this is an EPS, I'm not sure if there is anything to set.All colours in the file have been set to a Trumatch (or in some cases a Pantone process) number. Is there a setting for dot gain that I am missing somewhere or, because I'm using Trumatch and swatches that are printed to SWOP specs with dot gain, it's not an issue?
John McKercher
typesetter/production
Hartley and Marks Publishers
604-739-1771
From: Dan Margulis, 76270.1033@compuserve.com
Date: Mon, Aug 28, 2000, 10:16 PM
RE: [ColorTheory] EPSs and Dot Gain
John McKercher writes:>>We are doing a book cover that features an intricate pattern drawn in Illustrator, exported as an EPS and then placed in quark for seperations and film. If this were a tiff, I would know how to set cmyk settings for dot gain on the press we are running on but since this is an EPS, I'm not sure if there is anything to set.>>
There isn't. Once the CMYK values have been called for in Illustrator those are the values you will get. Hopefully the artist understood the phenomenon of dot gain.
>>All colours in the file have been set to a Trumatch (or in some cases a Pantone process) number. Is there a setting for dot gain that I am missing somewhere or, because I'm using Trumatch and swatches that are printed to SWOP specs with dot gain, it's not an issue?>>
You may be in luck if the colors are relatively bright. Such colors aren't much affected by dot gain. If you wish to be sure, open the Illustrator document in Photoshop at a low resolution for a look-see. If, with the proper CMYK Setup loaded in Photoshop, you observe that the image is too dark, then it should be edited before going further with it.
Dan Margulis
From: digital1@inmind.com, digital1@inmind.com
Date: Tue, Aug 29, 2000, 6:00 AM
RE: Re: [ColorTheory] EPSs and Dot Gain
Dan Margulis wrote:
>If, with the
> proper CMYK Setup loaded in Photoshop, you observe that the image is too
> dark, then it should be edited before going further with it.
Dan
I've been a fan of yours thru 3 books and 5-6 months on this list, and this is the highest degree of reliance I know of that you place in monitor display of tone or color. Do you have more faith in properly calibrated and profiled monitor display than you used to?
Les Schofer
From: Dan Margulis, 76270.1033@compuserve.com
Date: Wed, Aug 30, 2000, 10:43 AM
RE: Re: [ColorTheory] EPSs and Dot Gain
Les writes,>>I've been a fan of yours thru 3 books and 5-6 months on this list, and this is the highest degree of reliance I know of that you place in monitor display of tone or color. Do you have more faith in properly calibrated and profiled monitor display than you used to?>>
Not at all, the same amount as before. I've been calibrating monitors and using them as soft proofs for nearly 20 years now, and *do* have faith in them.
What I *don't* believe in is trusting them in areas where there's a known factor of human vision that causes us to have trouble perceiving what we see. Then, if there's an easy numerical way out, I take that. Since human vision is known to adjust near-neutral colors to neutrals, and since there is an info palette, I trust that in preference to my eyes to evaluate whether my grays are gray and my shadows and highlights neutral.
In this case, I suggested to John that he rely on his monitor to decide whether a certain image was too dark. I know of no attribute of the human visual system that would cause him to misjudge this, even if the monitor isn't calibrated perfectly, even if, for example, he turned the color off in the control panel and made the judgment in black and white.
The question "is this point being shown on the monitor in fact neutral" is one that human beings are very bad at answering but that machines answer rather well. The question "does this image look too dark" is a very tough one for machines, but easy for us humans. I distinguish the two types of question, and rely on the monitor in one case and not in the other, unlike some of mycalibrationist friends.
Dan Margulis
From: "Remaley, Dan
Date: Tue, Oct 30, 2001, 9:03 AM
RE: RE: [colortheory] Re: Reply to Dan_R on Dot Gain i n Separate Channels
Dan Remaley wrote:
> >
> > My response is that the 'curves' should be set to match a
> 'typical print
> > condition i.e. SWOP.
> > Yellow gain 20%
> > Mag gain 22%
> > Cyan 22%
> > Black 26%
> > Remember dot gain isn't a 'bad' thing, as long as its
> compensated for!
> > This set of numbers along with the solid ink density numbers
> represent GRAY
> > BALANCE at press.
> > If you decide to make the yellow the same gain as mag and
> cyan then you've
> > changed gray balance at press! Under controlled press
> conditions the yellow
> > would be to strong by 2% in the midtone. (yellow cast to
> neturals).
**********************
Steve Marsh wrote:
> Dan - what are the +/- tolerences for press deviation in tone at
> the 50% point in the CMK, and specifically the Y plates? I really
> care about K - but since yellow is the example you use...
>>>>> Marks my response
>>>>> The tolerences are +/- 3% midtone gain and +/- .10 Density
> I would suspect that the leeway more than blows out a 2% dot
> gain tweak in separation.
>>>>> The 'secret' is to keep the dot gains in 'balance' (all a
little heavy or all a little light)
> At these fine tolerences, if a printer has to hit a 2% target for
> proper grey balance - then I would guess that it will never be
> neutral anyway.
>>>>> Standard deviation (is +/- 2%) a lot of printer' vary as much
as 4%
That's why GCR is so important! It allows a 4-5%
change in color (even out of balance color)
i.e. (Mag +4% / Cyan -4% to be printed correctly.
> I could be wrong - but only 2% extra yellow in the midtones would
> not make or break that particular tone. If a highlight or perhaps
> quartertone, then perhaps yes (but I would say at least 5% gain -
> not only 2%).
>>>>> My offer still stands, send me your mailing address and I'll
sent you a printed sheet with UCR - GCR and Conventional scans. Also showing
a 2-4-6% deviation in a netural. Gray balance effects ALL colors.
> Putting this in real terms - if reproducing a bit of darkish silver
> metal - then having a midtone increase of 2-5% yellow would not
> hurt that much. If reproducing a bride in a white/off white wedding
> dress, then you would have to be very careful of the yellow tones
> in this 'light toned' region.
>>>>> This is true, to a point, if some condition exists on press
causing an increase in quarter-tone gain (excessive pressure - blankets -
ink issues) then you will see a difference in color. Are your press people
measuring dot gain?
> Of course UCR or GCR changes the equation for tones in the
> first half of the tonal range - but probably not enough for this
> hypothetical example.
>>>>>> Actually, GCR affects ALL colors all the way up and including 1/4
tones (depending where you start the cure and how much you use.
> If making separations for a publication that prints to a standard -
> you are best following that standard, otherwise the deviation will
> be your issue - since the printer is hitting a different target. There
> are less oportunities for 'colour correctino on press' in this type
> of ouput.
> Since all full colour work is targeted CTP to one press - we can
> attempt to get betting settings in pre press and aim for that
> press.
> Sadly the industry does not work that way.
>>>>> The 'problem' with the industry is that we have been measuring
solid ink density. We need to be measuring gray balance and dot gain - we
print DOTS not solids. Scan to gray - proof to gray - print to gray.
> 85% of work is supplied as is, pre separated. It is too hard to get
> people to separate to your inhouse standard (if it existed) - so
> what do you do?
>>>>> October's GATF World has good settings for Photoshop 6 - teach
your customers! Now that your customers are 'part' of your workflow - they
are also part of your profit and loss - educate them!
> You attempt to do things on press - which works very well in a lot
> of cases, even more so when only small shifts are needed.
>
> So to summarise - I agree with standards, and if in use they are
> great and it is good to aim at the set target, instead of attempting
> to force your own.
>
> But the print world is made of many sectors - and what works for
> some may not work for all. For our work, it would be nice if the
> press (or pre press or clients) could be run in a more 'scientific'
> fashion - but the 'free for all' that is my line of work does not
> make this possible or practical. The press is where the magic
> happens, if this is not possible - then things get expensive.
>>>> Your right, the press is "where it happens" but it can't be magic! Pick
up a copy of GRACoL or SWOP and begin the 'Process'. The press is very
limited in what it can do or not do, thats all determined up front in
scanning and pre-press. Measure and control - scans -films - proofs - plates
-presswork. Sounds like 'Process Control'. Color printing secret - Gray
Balance & GCR!
Dan Remaley/GATF
741.6860x450
From: Dan Margulis
Date: Tue, Oct 30, 2001, 11:28 AM
RE: [colortheory] Re: Dot gain curves
Dan Remaley writes,>>My response is that the 'curves' should be set to match a 'typical print
condition i.e. SWOP.
Yellow gain 20%
Mag gain 22%
Cyan 22%
Black 26%If you decide to make the yellow the same gain as mag and cyan then you've changed gray balance at press!>>
I in fact do recommend setting the yellow gain lower in my book. However, I do so because it is known to be theoretically correct and because it's no trouble to implement--not because missing the yellow gain by 2 points is any big deal. Missing the black by four points is also unlikely to create a major problem *unless* one is using a non-skeleton black printer, in which case it is a big headache indeed.
>>Remember dot gain isn't a 'bad' thing, as long as its compensated for!>>
It's unfortunate that so many printers don't share this wise philosophy, and understate their dot gains to their clients for fear of looking bad.
Dan Margulis
From: "Remaley, Dan", INTERNET:dremaley@gatf.org
Date: Tue, Oct 30, 2001, 1:05 PM
RE: RE: [colortheory] Re: Dot gain curves
> I in fact do recommend setting the yellow gain lower in my book. However, I
> do so because it is known to be theoretically correct and because it's no
> trouble to implement--not because missing the yellow gain by 2 points is
> any big deal. Missing the black by four points is also unlikely to create a
> major problem *unless* one is using a non-skeleton black printer, in which
> case it is a big headache indeed.
>
> >>Remember dot gain isn't a 'bad' thing, as long as its compensated for!>>
>
> It's unfortunate that so many printers don't share this wise philosophy,
> and understate their dot gains to their clients for fear of looking bad.
I agree Dan, yellow isn't as important as the other colors, the reason these numbers "work" is because they are based on a standard ink set i.e. SWOP. For example: If your using a Rhodamine red instead of a Rubine Color magenta, the gray balance will need to be adjusted for the less (-Cyan) magenta ink. It is unfortunate that most printers don't understand 'color reproduction'. That's why I developed my seminar "Process Control in Print Production". It takes you through the entire printing process and what to measure for correct process control. Here's some stats I raised at the GATF Shetfed conference 2 years ago-
Out of 250 people-
Measure SID - 99%
Measure midtone gain 48%
measure Print Contrast 25%
measure GRAY BALANCE - 1-personSend me your mailing address and I'll send you some printed sheets
explaining this process.
Dan Remaley/GATF
412.741.6860x450
From: Stephen Marsh
Date: Tue, Oct 30, 2001, 4:50 AM
RE: [colortheory] Re: Reply to Dan_R on Dot Gain in Separate Channels