callas pdfToolbox vs. Adobe onboart tools

[cmoke73]

Hi everybody.

My following question is a larger topic, but I just want to keep it as simple as possible: PDF export to InDesign with a press-ready color management.

The framework conditions: MAC OS, InDesign CC21, Adobe DC Professional, callas pdfToolbox (as a plugin or use independently of an application). The output (ISO Coated V2 for the cover and SC paper (ECI) for the content) goes to a printing house.

In recent years, our workflow has been as follows:

- do the job with InDesign

- Export PDF

- Separating the pages into individual pages

- Converting colors in Acrobat using the pdfToolbox plugin (this step for SC paper content only)

- Profiling PDF X4 (with custom profile) in Acrobat with pdfToolbox plugin

After that, the catalog was ready for printing. The conformance in Acrobat shows (for the content): PDF/X-4, Identifier is FOGRA40 and Profile Info is SC Paper (ECI).

I'm wondering if I don't use the plugin and create the color conversion job using the Adobe tools, can I get the same result with it? Please see the screenshot showing the settings in the InDesign exporter.

Of course I've already tried it, but in fact it was a big visual difference to the result with the callas pdfToolbox. So something might not be right there.

Color management is a big topic, I know, but what's the mistake in this case? To me the way with onboard tools sounds reasonable. 🙂

I would appreciate your answers

[rob day]

Hi @cmoke73 , The job isn’t going to be imposed for, or print on the same press sheet, so I think you would be better off creating a separate document for the cover pages— cover, inside cover, inside back cover, and the back cover. Then the cover document can have the ISO Coated V2 CMYK profile assigned, and exported to PDF/X-4 with ISO Coated V2 as the Output Intent. The interior can have the SC paper (ECI) as its CMYK profile assignment and be exported to PDF/X-4 with SC paper (ECI) as the Output Intent.

If you do that I don’t see why you would need to use Callas pdfToolbox at all—the two documents would have the correct CMYK conversions and PDF X Output Intents.

[cmoke73]

Hello rob

This is what I did: separate sheets with different profiles. I'm just wondering if you get the same result when exporting with profiles in InDesign and with the Callas application. It really doesn't look like it on my screen.

[rob day]

I can’t help with Callas, but with AcrobatPro make sure you have Output Preview open. When you Export to a PDF/X standard, AcrobatPro will default to the Output Intent for the Simulation Profile and you should get a match between InDesign and Acrobat. Here my document has Coated GRACoL 2006 as its CMYK assignment and my PDF/X-4 Export is to Document CMYK:

Output Preview:

[cmoke73]

Hi Rob.

Sorry for my late reply, I had to be in the office at my true color monitor to check a few things before replying.

That sounds logical for me. It could be the easiest and also the fastest way to get ready-to-print documents. We've been using this (callas pdfToolbox) plugin for a long time (before I was here) and I'm wondering if we could do without it. On the other hand, I hoped to get a deeper insight into color management by comparing both methods.

As an example, I prepared 4 sheets with different output:

1. without profile and without color converting

2. do all the work with InDesign PDF export tool

3. one-Step-Job in callas (conversion with an already created profile)

4. two-step job in Callas (first the color conversion tool, then profiling with PDF X4)

And the result amazes me. Especially between point 2 (which is how I would like to do it) and 4 (which is how we have been doing it all along). The biggest difference in the CMYK colors is usually seen in yellow. The colors become "warmer" due to the profiling from InDesign. For the paper we use (SC paper) that might not be the best. The paper itself has a warm note. Strangely there are no color shifts when converting RGB colors.

So, I´m confused. 😞

[Laubender]

Hi @cmoke73 ,

you could also discuss this issue at hilfdirselbst.ch.

There should be a lot of users of the Callas pdfToolbox who can assist.

Regards,
Uwe Laubender
( Adobe Community Expert )

[cmoke73]

Hello Uwe.

OK, I did. Thanks.
Nevertheless, I do not reject an answer in this forum. 🙂

[rob day]

Am I understanding correctly that you are building CMYK colors in InDesign and using the same builds in the cover and interior documents—the document CMYK colors have the same CMYK values, but different CMYK profile assignments?

Can you share the SC paper (ECI) profile?

[cmoke73]

I have defined custom CMYK colors in InDesign and use them for elements on the cover and content pages. Only when I export the documents (content and cover are different documents) do they get their own profile. Or at the latest when I do it with the pdfToolbox (depending on how I will use it later).

The profile I'm using I downloaded from: https://www.color.org/registry/SC_paper_eci.xalter

[rob day]

The ISO Coated V2  and SC paper (ECI) profiles are so similar I wonder if you are doing more harm than good by trying to apply color managed conversions to your built CMYK colors? Offset printing is a variable process—the actual profile of the press could change depending on the ink densities, even during the run.

If I compare the 3D plots of the two profiles in Apple’s ColorSync Utility the profile gamuts are almost identical, they have similar black generations, and both have a total ink limit of 300%.

If I assign the profiles to a CMYK doc with the same values there is very little change in appearance, so trying to adjust the output values via a conversion to compensate for the minor appearance differences hardly seems worthwhile.

[cmoke73]

They may have similar values, but you can clearly see a visual difference. And more importantly, the printer asked for profiling. No choice. 🙂

[rob day]

If you care about matching appearance then you would have to use Edit>Convert to Profile... rather than Edit>Assign Profiles... Here I started with a document that has ISO Coated assigned as its CMYK profile (bottom), duplicated the doc and converted its CMYK colors to the SC Paper profile (top). The converted document now has new CMYK values, but with SC Paper assigned as its profile, so its native color appearance doesn’t change:

Now if I Export both docs to PDF/X-4 with the Destination set to Document CMYK everything matches and the exported PDFs have the correct PDFX Output Intent:

A few things to watchout for, all the native CMYK colors get converted to new CMYK values except for default [Black]. In the above 0/100/0/0 magenta gets converted to 1/100/13/0.

Placed images do not get converted, so make sure any placed images are RGB with embedded profiles, so the images are converted from profiled RGB to document CMYK on the export.

[cmoke73]

If you care about matching appearance then you would have to use Edit>Convert to Profile... rather than Edit>Assign Profiles...

That´s good hint.

Placed images do not get converted, so make sure any placed images are RGB with embedded profiles, so the images are converted from profiled RGB to document CMYK on the export.

I'm afraid I can´t avoid having different kind of pictures (RGB and CMYK).

There is more than one source for the photos. The correct conversion should therefore take over the application when exporting or at the latest when profiling with callas.

Maybe this is why we use complementary software (?).  😞

[rob day]

If you are forced to place CMYK  just make sure the image has an embedded profile and the document’s CMYK Policy is set to Preserve Embedded (not Preserve Numbers (Ignore Linked Profiles)). See Link Info to check the image profile.

In that case if the embedded profile conflicts with the document’s CMYK profile the image will get converted to the Export Destination CMYK profile on Export. If the image has no source profile there’s no way to make a color managed conversion with either InDesign or Callas. I would convert CMYK with no source profile back to a large RGB space like AdobeRGB, color correct, and place with the profile embedded.

[cmoke73]

All right, I see. I need to find some time to review and adjust those hundreds of images (mainly PS docs).

[HeraklitePrepress]

Hello.
For such purpose, even if the best solution would be to drive a color server, you also could "maximize" your work using this InDesign script: https://www.rolanddreger.net/de/1/farbmanagement-in-adobe-indesign/

It might be helpful.

Sincerely.
Axel

[cmoke73]

I missed the link before. Nice tool! Thanks.

[Laubender]

Note: A complementary discussion started in German at hilfdirselbst.ch:

Acrobat vs. callas pdfToolbox - Unterschied in der Farbkonvertierung.
cmoke, 18. Jan 2023, 10:50
https://www.hilfdirselbst.ch/gforum/gforum.cgi?post=585308#585308

Regards,
Uwe Laubender
( Adobe Community Expert )

[cmoke73]

Thank you Uwe for your hint!

[HeraklitePrepress]

Dear user I read with interest this post.

First, if you want to properly use the Photoshop eyedropper as a real densitometer with Lab values, be sure the Intent has been choose Mode Absolute Colorimetric has been checked in the Color Settings.

Secondly, IMHO, they are many factors to discuss in order to compare apples to apples.
SC_paper_eci and ISOcoated_v2_eci ICC profile are very different indeed.
Not only the TAC but moreover the White Point.
It is more "yellowish" and less "luminous" in the former (L89 a0 b5) and more "neutral" and "luminous" with the latter (L95 a0 b-2).

You mentioned using Callas pdfToolbox for color conversion.
So, you perform it after having exported a PDF from the In Design source file.
What profile do you use? Is it a normal conversion or a Device Link conversion?

Be aware to the cumulative conversions from the departure to arrival.

Let me know.
Sincerely.

[rob day]

I rechecked the SC Paper TAC and it is 270% vs 300% for ISO Coated. Thanks

[HeraklitePrepress]

Hello Rob.
This is indeed thrue for the optimazed ECI version AKA ISOcoated_v2_300_eci.
The historical one, namely ISOcoated_v2_eci  has a 329,9% TAC.

  

[Laubender]

@HeraklitePrepress asked: "Is it a normal conversion or a Device Link conversion?"

As far as I can see from the German discussion at hilfdirselbst.ch a Device Link conversion is in play with the Callas pdfToolbox software. And that's the criterium that I say stay with pdfToolbox.

Regards,
Uwe Laubender
( Adobe Community Expert )

[rob day]

Hi Uwe, I think DeviceLink profiles work well to fix CMYK color that has been convertd into the wrong space—if @cmoke73 used ISO Coated for the interior its 300% TAC would have to get adjusted.

But the question might be why work with CMYK color at all. If I posted a question here about placing CMYK images, everyone would tell me to always place RGB—if CMYK images are a problem why is it OK to build InDesign swatches as CMYK?

Rather than building my source colors in a CMYK space, which might be wrong, I could create the colors in a large gamut RGB space, or device independant Lab—Pantone Solid color swatches set to process would be in the Lab space. I could then assign either ISO Coated or SC paper without the Lab color’s appearance changing, and make a single Lab-to-CMYK conversion.

[HeraklitePrepress]

Dear Uwe.
pdfToolbox offers such transformations indeed.
But you should load your own in order to use them.
So, that implies building them beforehand in another dedicated software, unlee you previously bought some.
In a second instance, I can stat, after some tests, the results differ with the same DVL depending on the software to run them. Which seems counter intuitive by default.

Sincerely.
Axel