Participant

Answered

Less CMY more K for offset printing

Forum|Forum|4 years ago
April 28, 2021
4 replies
1859 views

Hello, I work in color Management for art book projects to be printed in OffSet. I hear that is possible to drop down CMY color and replaced it with K ink. With this, I will get less % of the total ink.

For example:

Workin with FOGRA 51 profile My Darkets part is up to 320% of total ink. I'm wondering if it's a program, plug-in, or a "manual" way to make a proportional and proper CMY% ink extract and replace it with Blak ink.

Hope I am clear, English is not my thing.

Many Thanks

This topic has been closed for replies.

Correct answer TheDigitalDog

The obvious question is: why? What is it you're trying to achieve?

Best avoid the old, CMYK engine like the plague. Yes, you can 'edit' those parameters but they are nothing like what a specific ICC profile provides, nor are they based on the data that was used to build such profiles like FOGRA 51.

You'd need some profiling package and measured data that mimics the target printing you desire and use it to alter UCR/GCR.

See:

http://digitaldog.net/files/CMYKPart1.pdf

http://digitaldog.net/files/CMYKPart2.pdf

Stephen Marsh

Community Expert

I don't have time now for the long post this question requires and if English is not your first language it may be hard.

To start, take a look here:

https://www.colormanagement.org/en/isoprofile.html#coated_FOGRA39_GCR_bas

https://www.colormanagement.org/download_files/coated_FOGRA39_GCR_bas.zip

What you really need is to use ICC profile creation software and or ICC device-link profile creation software to create your own profiles from various characterisation or measurement data for the required specifications.

P.S. Generally speaking, "Ink Saving" is not just about reducing total ink values in the shadows – it is about replacing the gray component throughout the image's colour and tonal range.

Juan AmadorAuthor

Participant

Thanks Stephan.
With this info, I will keep on searching and learning the ICC profile, photoshop, and Offset structure and components.

Yes, English is not my language. Hard effort to explain (learning) and I can't imagine how much effort for you understand. Realy appreciate.

Norman Sanders

Legend

In my experience most art books have a run length more suitable for sheet-fed presses than for web. Usually, in sheet-fed, ink volume is not a major cost item. Certainly, if changed, it could affect art book image quality.

If the art book is destined for web, although ink is a cost to be considered, I would still look elsewhere for items on the cost sheet for economy. Simply, if the subject is art, each production compromise may affect sales significantly.

If you were to choose Edit > Color Settings > CMYK > Custom CMYK you would see the difference in Gray Ramp as you go from the default of Medium to Heavy. (Note: Although total ink limit in the illustration is set to 300% rather than your 320% the effect in the ramp shape is unaffected.)

Oddly enough, if the art consists of photographs and includes flesh tones -- portraits, for example -- I have found it helpful to change the GCR from Medium to Light. If you notice, that change introduces the black at about 50% and is less likely to be part of the caucasian flesh tone mixture.

Juan AmadorAuthor

Participant

Thanks Norman.

I work in art's book's and catalogs project (paintings, photography, sculpture, etc) that they will be printed in OffSet CMYK analog.
What I have to do is to reproduce as good/similar as possible the original image or 'painting'. In general, I have to use a specific ICC profile (like FOGRA 39, PSO Coated v3, or others depending on the paper we use and the place/country we do it) so I don´t know what happened if I go where you told me and change the GCR in .../Custom CMYK. When I do that looks like I change the ICC color profile. I only have a EuroStandar Coated for example, and I have to keep the PSO couted v3.

What I need is to change each % color of the CMYK (like GCR does) of my images without changing the ICC profile (Coated v3 for example). I don´t know if this is possible.

Thanks a lot all of you.

D Fosse

Community Expert

The obvious question is: why? What is it you're trying to achieve?

c.pfaffenbichler

Community Expert

Another point: If you need to convert CMYK-to-CMYK you may want to look into Device Link Profiles.

Edit:

software to create device link profiles

c.pfaffenbichler

Community Expert

That’s (in part) what GCR is for (also UCR) and is part of CMYK ICC-Profiles.

If you can’t find an existing profile for the print condition that meets yout TAC-needs (Total Area Coverage) and need to edit or create ICC-Profiles you will likely need specialized software.

Manually faking GCR with Adjustment Layers for example does not seem exactly recommendable.

Juan AmadorAuthor

Participant

Many Thanks!!!!

Sorry, but, where I work that GCR o UCR?

Yes, doing it manually is insane. So far I'm working it like this when I
need it.

c.pfaffenbichler

Community Expert

As Gray Component Replacement (and Under Color Replacement) are part of the CMYK ICC Profiles you should either look into the dedicated software for creating ICC and Device Link Profiles or look for a service provider who can create one for your specific task.

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded