Dan Margulis Applied Color Theory

The Future of Custom Separators

Future of custom separators?
Posted by: "aliruleweb"
Mon Mar 16, 2009 4:36 pm (PDT)

Hi all,

In doing some research regarding the adoption of G7 and SWOP3 by some of the printers we send files to, several questions have started to percolate in my mind regarding the future and need for high end separators in the printing industry. This is a very disturbing concept for me as I've been working in a high end separator environment for 25 years. I think I need a little reality check.

A little back ground about our images:
I work for a prepress house where we convert all our RGB and provided CMYK images into one basic in-house custom profile using an action to blend several conversion techniques to achieve the best separation with the most channel detail targeting the end printing conditions. This has been a very successful process which has evolved over the years based off of our experience on press across many projects. We then use a multitude of techniques to reduce skin texture, achieve critical sample match and enhance shape and detail. We'll even re-channel mix a single item in an image to have a long black with in a short black separation. Additionally, we're creating custom CMYK quad tones starting with a half tone then using channel mixer and curves to get our final result. In all cases, we create contract proofs with a Fuji Final Proof calibrated to the clients printers system that are balanced to on press checks.

Conditions we separate to and their success:
*In all cases, the client has chosen the printer. We are never involved in that selection process.

1. Web printers calibrated to SWOP who use our files as is (no other conversion). These printers can match our contract proofs fine.

2. Web printers calibrated to SWOP who convert our files to adjust and control GCR using who knows what input profile as we do not tag our files. Depending on the printer, we've seen mixed results.

3. Web printers calibrated using G7 who don't convert our images. Images don't print too poorly but there is a lot of room for improvement hence my research after the fact.

4. Web printers calibrated using G7 who do convert our images. They can't match their own in house proofs but they are able to run closer to our Fuji proofs.

My questions:

- If the printer converts our files, who is then responsible for how the job prints? Us or them? I know this is a some what rhetorical question. These tend to be the group who have trouble matching our proofs not surprisingly.

- If a client has been sold the benefits of a G7 process on press and the printer is going to re-seperate our files any way, why don't we just send RGB?

- If we are having to use devise link profiles to simulate the G7 process on our Fuji proofing system, why don't we just go to an Epson proof. What is the benefit of the laminate system when the Epson can do a paper simulation?

- First there were camera separations, then scanner separations now profile separations. In each case the high end separator always tweaked the separation once it was in CMYK. What is the argument for this continued practice?

I would appreciate any and all comments.

Thanks,
Alison Walker
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Re: Future of custom separators?
Posted by: Dan Margulis
Wed Mar 18, 2009 7:31 am (PDT)

Alison writes,

In doing some research regarding the adoption of G7 and SWOP3 by
some of the printers we send files to, several questions have
started to percolate in my mind regarding the future and need for
high end separators in the printing industry. This is a very
disturbing concept for me as I've been working in a high end
separator environment for 25 years. I think I need a little reality
check.

The need for professional separators is far less than what it was years ago for the obvious reason that clients can now do it themselves. Those who don't care about quality or (hopefully) are skilled themselves have no need for somebody to do this work for them.

That still leaves clients for the service, but to keep them, you have to be *decisively* better quality-wise than they would be if they tried it themselves. You have to be able to achieve consistent quality on press, often in spite of the printer the client has chosen. Printers are generally quite ignorant of separation issues. Allowing them to ruin jobs at a whim is fatal, so you have to step in where needed.

Conditions we separate to and their success:
*In all cases, the client has chosen the printer. We are never
involved in that selection process.

This has been normal in the industry since the beginning of time.

1. Web printers calibrated to SWOP who use our files as is (no
other conversion). These printers can match our contract proofs fine.

Ditto.

2. Web printers calibrated to SWOP who convert our files to adjust
and control GCR using who knows what input profile as we do not tag
our files. Depending on the printer, we've seen mixed results.

Not surprising. My suggestion is that your instructions should include a statement to the effect that the GCR and other separation settings in the file are critical to print quality, and that reseparation by the printer will result in the rejection of the printed job. I would print this on a red label and paste it on the bottom of the print order.

3. Web printers calibrated using G7 who don't convert our images.
Images don't print too poorly but there is a lot of room for
improvement hence my research after the fact.

If they are printing to a standard, any standard, as long as they are printing to it consistently you should be able to adjust to it.

4. Web printers calibrated using G7 who do convert our images. They
can't match their own in house proofs but they are able to run
closer to our Fuji proofs.

An infinite number of monkeys with an infinite number of typewriters...

My questions:

- If the printer converts our files, who is then responsible for
how the job prints? Us or them?

Them. They have seen that you clearly indicated, by your failure to embed a profile, that you did not wish them to reseparate your file, and they have done so anyway. The situation is exactly the same as if they had entered your image files and recorrected them. If you happen to like the result they got, by all means accept it. However, unauthorized changes like these give you and your client a right to reject the work if it is not to your satisfaction. The question of whether ink densities are within proper tolerances is not relevant.

These tend to be the group who have trouble matching our proofs not
surprisingly.

No, it's not a surprise. The mere fact that they would guess at and assign a profile, let alone reseparate the file, indicates that they have little regard for quality.

If a client has been sold the benefits of a G7 process on press
and the printer is going to re-seperate our files any way, why
don't we just send RGB?

This is like asking if the client is going to leave a large amount of cash in plain sight on the front seat of his car, wouldn't it be a better idea to leave the door unlocked so that anyone wishing to remove it will not have to break the window to do so.

If we are having to use devise link profiles to simulate the G7
process on our Fuji proofing system, why don't we just go to an
Epson proof. What is the benefit of the laminate system when the
Epson can do a paper simulation?

The quality of modern large-format printers has gotten so good, and the speed improved so much, that it's hard to justify something more expensive. There are many ways of adjusting such printers to achieve results good enough for contract proofs.

First there were camera separations, then scanner separations now
profile separations. In each case the high end separator always
tweaked the separation once it was in CMYK. What is the argument
for this continued practice?

Camera separations don't produce a digital file, so there was no electronic tweaking. Scanner separations were pre-corrected--that is, the scanner operator should have set endpoints and fixed obvious color deficiencies. So the game is different today. CMYK correction doesn't do well with bad originals. Where it shines is in small contrast enhancements, as a recipient of channel blends, and in adjustment of shadow values. If the file has to end up in CMYK anyway, these tweaks are valuable.

Dan Margulis
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Re: Future of custom separators?
Posted by: Stephen Marsh
Mon Mar 23, 2009 4:06 am (PDT)

Alison Walker wrote:

- If the printer converts our files, who is then responsible for how
the job prints? Us or them? I know this is a some what rhetorical
question. These tend to be the group who have trouble matching our
proofs not surprisingly.

As you know Alison, it depends on who you are asking! The customer of the printer would say that the printer is responsible. The printer would say that they are not responsible, however you may not be given the chance to take over from them and have to work around the issue (as has always been the case).

It all depends on your clout, being a customer of a printer does not always mean that you are always right, despite that old saying.

"Us or them?" sadly it often comes down to this, rather than a "partnership" where both parties are communicating (this is not an attack on you Alison, just a general comment).

- If a client has been sold the benefits of a G7 process on press and
the printer is going to re-seperate our files any way, why don't we just
send RGB?

Totally reseparate as in ICC, or regenerate as in DLP (perhaps honouring or repurposing the K channel data and or other areas of the original separation values)?

Most of the advantages are lost if they totally reseparate the image and seriously alter the K plate and relation to CMY etc. If you are lucky they may have somebody clued in enough to repurpose the original K plate into the new seps. The gamut compression/mapping has taken place, so this aspect you can control rather than relying on their conversion. Even if handing off RGB, one could dupe the file and convert to CMYK, before going back to an accepted tagged RGB file (perhaps accounting for any density loss in the final RGB file).

- If we are having to use devise link profiles to simulate the G7
process on our Fuji proofing system, why don't we just go to an Epson
proof. What is the benefit of the laminate system when the Epson can do
a paper simulation?

I am not familiar with this device. Does it produce halftones similar to the final press? Is this critical for you?

- First there were camera separations, then scanner separations now
profile separations. In each case the high end separator always tweaked
the separation once it was in CMYK. What is the argument for this
continued practice?

The argument is crafted colour vs. commodity colour. The ability to outdo your competitors (or to fail by being an "unlucky expert") vs. average uniformity. Again, many of these direct benefits are lost if the CMYK is reseparated via a simple ICC transform.

The technology and the print market decided this issue long ago (it just took a little longer than with typesetting), however there are still some that use the services of folk such as yourself, or acquire the knowledge to create above average separations for a given condition (usually with post separation CMYK edits).

Stephen Marsh
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Re: Future of custom separators?
Posted by: J Walton
Mon Mar 23, 2009 1:32 pm (PDT)

If we are having to use devise link profiles to simulate the G7
process on our Fuji proofing system, why don't we just go to an Epson
proof. What is the benefit of the laminate system when the Epson can do
a paper simulation?

Sorry to be jumping in on this so late, but if I can add a little bit I'll try.

I assume by Fuji proofing system you mean the FinalProof. I have some experience with that system (although it's been a few years since I used one, and more than 5 since I helped set one up).

We purchased the FinalProof to replace the 4-up proofs we were doing with the Creo. Much better than the Creholes, and better overall than the Epsons.

The advantages over inkjet?

: : Well, you don't need to do paper simulation since you can laminate to the exact stock you will be running through press.

: : You will get a higher ink density using a laminate system - at least a few years ago the Epsons couldn't get quite dark enough.

: : Halftone dots are an important part of some proofing systems, since it's hard to catch moires on an inkjet proof without halftones.

: : If you set things up right you can shoot 1-bit tiffs that have already been screened, so you have the exact same rosettes on your FinalProof as you do on your press run. This is, of course, if you are the printer and can control the screening.

The disadvantages are mainly cost-oriented - inket proofs are *much* cheaper, but don't look *much* worse. And the big systems (GMG, EFI, etc.) do some method of halftone screening, although you'll often find it's not that important anymore unless you are doing a lot of product shots.

We actually were not using Device Link profiles with the FinalProofs. We used their calibration utility and used curves to tweak the color until it matched our press *exactly*. It was not easy, and it was incredibly expensive (in material usage), but we managed to get it right on the money without any profile tweaks. I like that method because we didn't have to worry about blacks getting remade or anything like that. The downside to that is the ink traps didn't look quite right, as they never seem to look right without a profile.

We brought in Eric Magnusson (Left Dakota) to help us with the set up of our inkjet proofers, and while he was going to use his own product (Link-O-Later) on the FinalProofs even he acknowledged we were so close with the curves it wouldn't do us any good.

Hope this helps...

J Walton