Really Dumb Question - SWOP to GRACoL

[chevalier]

When converting a document in InDesign from SWOP to GRACoL it is yielding completely different builds in colors.

Example: Cyan-20, Magenta-10, Yellow-50, Black-100 becomes Cyan-77, Magenta-67, Yellow-82, Black-89
Dumb question: WHY?

 

[TerryWyse]

When converting a document in InDesign from SWOP to GRACoL it is yielding completely different builds in colors.

Example: Cyan-20, Magenta-10, Yellow-50, Black-100 becomes Cyan-77, Magenta-67, Yellow-82, Black-89
Dumb question: WHY?

Couple of reasons....

* SWOP and GRACoL describe two different color spaces....if you want the color to *visually* match from one space to the other, CMYK values will need to change.

* You're allowing it to *convert* the colors. You didn't say specifically in what part of the workflow this is happening (exporting a PDF or importing images or possibly converting the InDesign file from one profile to another?). In any case, what you NORMALLY want to do in a case like this is have Indesign "Ignore Linked Profiles/Preserve Color Numbers". On the other hand, if you want the SWOP document to retain the same visual appearance when printed to GRACoL specs, then you want a conversion to take place.

Judging by the numbers you posted, it sounds to me like you're going from CMYK values that have a very high percentage of GCR to something of a normal GCR level but with possibly black point compensation happening in the profile conversion.

The only way you're going to get a more-or-less desired conversion in this case is to use device link profiles instead of a standard ICC conversion (in my opinion).

Terry

 

[michaelejahn]

because they are different

because they are different

When converting a document in InDesign from SWOP to GRACoL it is yielding completely different builds in colors.

Example: Cyan-20, Magenta-10, Yellow-50, Black-100 becomes Cyan-77, Magenta-67, Yellow-82, Black-89
Dumb question: WHY?

Because they are completely different printing processes. Because they start with the assumption that the paper color is different and the ink densities.

Also because InDesign is probably a terrible place to do this, but hey, you already know that now...

So, in a perfect world ( we don't happen to live in one BTW ) you would work assuming GRACoL and then simply change the output intent and let the printer sort that out.

a simpler explanation might be that if you wanted two colors to match using two different printing processes on two different paper color - that you would need two different CMYK recipies to make two colors visually match.

I suppose my question might be "why are you doing this ?" This is an exercise in frustration.

Hope this helps, but probably doesn't

click on this link and download the poster;

http://www.idealliance.org/sites/de...elines 2011 Poster_print only_Oct10-final.pdf

open that PDF in Acrobat and scroll down to the bottom chart.

Note that even something as simple as a grey is different.

 

[CMY Killa]

Also because InDesign is probably a terrible place to do this, but hey, you already know that now...

I don't mean to hijack this thread, but I have the same issue only backwards.

I was wondering was is the best method to convert Gracol to Swop or Vice versa since indesign does seem to suck.

Any Suggestions?

 

[mattbeals]

device link profiles to map CMYK to CMYK directly.

 

[CMY Killa]

device link profiles to map CMYK to CMYK directly.

I work in an in-house design department. I do the pre-press for files sent out to printers.

Where would I implement this conversion? I have profilemaker to make the device links, but we don't have any RIPs other than colortuner for proofing.

Currently we send out indesign files but since adobe doesn't support device link profiles would we have to change our work flow to a PDFX.. workflow/output ? and/or is there a software solution we can use?

 

[mattbeals]

Using PDF/X- is always a good idea. You could use callas pdfToolbox or Enfocus PitStop Pro to apply the device link and verify that the file is PDF/X compliant. But you don't need device links to work with PDF/X. You may be better off not getting involved with device links and letting your print provider handle that for you. Really what I would suggest is get into a PDF/X-4 or a PDF/X-1a (only if you absolutely have to) workflow. Part of what PDF/X-1a and X-4 files contain is an output intent which is a way of describing the color space of the document. Like I'm a PDF/X-4 US Web Coated SWOP v2. It tells us that the color space is US Web Coated SWOP v2. Very clear, very specific. Print providers then have a clear understanding of how the color was separated. With that information they can decide how to handle the color to fit their needs.

 

[CMY Killa]

We are trying to make a idiot proof file for 3rd world vendors who don't use gracol and some of who seem to just take our gracol files and run them with no conversion or processing in between. We have had excellent results with North American printers. It seems to me that some of the cost savings in China come from just skipping these conversion steps. They strip the profile and run it as if were swop.

Any recommendations?

 

[JoshB]

Smart-ass answer: buy American.

Longer answer: You could try converting to SWOP yourself if you believe that's how they set up. Seems more likely that they have no color management at all, however, and that this may not be any better in the end.

You could check your color bars and try to figure it out from there. If they only run on one press you might even be able to do a little compensation on your end to help things along.

Don't know if I'd blame it on the Chinese though. I've seen two American offset shops that don't seem to do even linearization, let alone profile conversion. Seems like you should be able to find out what they are doing just by asking.

 

[CMY Killa]

Seems like you should be able to find out what they are doing just by asking.

yeah right?! By the time our question gets through the broker to the chinese plant and back to the broker and back to me it the answer is "we will try to do better next time".

The answer all along was only hire certified printers and try to print locally when possible. But that isn't an answer bean counters like.