Acrobat-Preflight fails for ICC profile check

[phph]

Dear Affinity Users and Developers

We’re just in the process of evaluating Affinity Publisher (tested with 1.7.0.305 and 1.7.0.312) and we’ve come upon a problem with the PDF/X export:

In our workflow our print PDF files are checked in Adobe Acrobat against the preflight profile PDFX-ready Sheetfed Offset Classic HQ V1.5. Among other things this profile checks the MD5 checksums of the used ICC profile against a pre-defined list of profiles known to be appropriate for offset printing.

When exporting a PDF as PDF/X-1a with the ICC profile ISO Coated v2 300% (ECI) from Affinity Publisher the preflight returns this error:

Quote

Output Intent not suitable for printing (unknown ICC profile) (V2.4)

Looking at the preflight report in the section Output Intents I noticed a difference between a PDF exported from InDesign and Affinity Publisher:

• The Output Intent is stated as ISO Coated v2 300% (ECI) for the InDesign-PDF and as ISO Coated v2 300% (ECI) (Custom) for Affinity Publisher
• The Color Management Module had a value of HDM (InDesign) and lcms (Affinity Publisher).
• Primäre Zielplattform (in English probably: Primary Target Platform): empty (InDesign) and Apple Computer, Inc. (APPL) (Affinity Publisher)
• Profil erstellt mit (in English probably: Profile created with): Heidelberger Druckmaschinen AG (HDM ) (InDesign) and lcms (Affinity Publisher)
• The other fields were the same in both files.

So I suspected this to be the reason for the different MD5 checksums. But not being an expert on the ins and outs of PDFs and colour management I turned to HilfDirSelbst.ch where we discussed this (in German) in this thread. Olaf Drümmer of callas concluded (my translation):

Quote

I assume when exporting to PDF Affinity [Publisher] loads the profile from RAM rather than from disk and writes it to the PDF.

So the profile was probably loaded from disk (with the help of Little CMS) when opening a document requiring that profile. Then it’s being used while working on the document and on exporting to PDF it’s written from RAM to the PDF file. Because that probably also happens using Little CMS, the field Creator of the profile in the PDF is filled with "lcms".

That’s not a bad approach – but unfortunately the checksums can’t match. Little CMS is neither better nor worse than other CMMs (either Adobe or Heidelberg)

[…]

So the question is

• Is Affinity Publisher correct in changing the meta-data of the profile when writing the PDF file?
• And if so: Would PDFX-ready need to append their list of MD5 checksums to include those of profiles created with lcms?

Any insights and suggestions would be greatly appreciated!

Best

phph

[Shoku]

PDF/X is based on an error in thinking by the engineers. This is obvious by the logic behind the implementation. IN PDF/X assigning a CMYK profile to the document removes profiles embedded in any images. This untagging of individual images can lead to color errors if the PDF/X document Output Intent is different from the original color space of the document images.

A universal CMYK document output intent is also problematic because every offset press has its own color space - ISO standards are just "standards" we use to measure from when profiling a press. When a press is "profiled" they will have there own unique color space based on the inks used and the substrate printed on, combined with the characterization of each press.  PDF/X sets one standard based on a Color Profile that will have nothing in common with any real world press.

This discrepancy is the same one that affects the Pantone Matching System. To faithfully reproduce a Pantone Solid Color all the print specifics listed in the Pantone Swatch Book will need to be met exactly - paper type, ink type, and press. This never happens for Pantone or for "standard" CMYK profiles. 

Because of these limitations, it is best to color manage each image individually, embed a color profile into each image and export with no conversion and preserve the image profiles, and not use PDF/X.  The pre-press department at the printshop will then be able to confidently color manage the file for their press.  When we receive PDF/X the first thing we do is remove the Output intent because all it does is add a layer to proper color management and can be a false flag.

Edited May 19, 2019 by Shoku

[thomaso]

On 5/17/2019 at 1:16 PM, phph said:

When exporting a PDF as PDF/X-1a with the ICC profile ISO Coated v2 300% (ECI) from Affinity Publisher the preflight returns this error: 

Quote

Output Intent not suitable for printing (unknown ICC profile) (V2.4) 

I don't get an error message when exporting to X-1a with ISO Coated v2 300% (ECI) .
Also the result looks fine for preflight, see screenhot:

 

 

19 hours ago, Shoku said:

IN PDF/X assigning a CMYK profile to the document removes profiles embedded in any images.

Not to me. See attached a preflight screenshot for PDF/X-3:
– No preflight complaints
– Output intent = document's color profile (as selected and expected)
– Three Device color spaces

20 hours ago, Shoku said:

This untagging of individual images can lead to color errors if the PDF/X document Output Intent is different from the original color space of the document images. 

Not if the resource profiles are converted to the output intent on export. This is the use of color profiles in general: to possibly be converted from one to another without harm.

[Shoku]

It appears that you have a custom Output intent "ISO Caoted v2 (ECI) "Custom)", and yet multiple pictures (bilder) in CMYK, RGB, and Black (schwarz). IF all images were converted to CMYK you would not see RGB and Black pages in the page list, nor Gray in the color list.

[MikeW]

16 minutes ago, Shoku said:

It appears that you have a custom Output intent "ISO Caoted v2 (ECI) "Custom)", and yet multiple pictures (bilder) in CMYK, RGB, and Black (schwarz). IF all images were converted to CMYK you would not see RGB and Black pages in the page list, nor Gray in the color list.

PDF/X3 allows for RGB tagged (ICC) images. The deviceColor is also allowed.

[thomaso]

36 minutes ago, Shoku said:

It appears that you have a custom Output intent "ISO Caoted v2 (ECI) "Custom)", and yet multiple pictures (bilder) in CMYK, RGB, and Black (schwarz). IF all images were converted to CMYK you would not see RGB and Black pages in the page list, nor Gray in the color list.

Yes. This is as it may and should be.

Whereas in the screenshot above you see the same .afpub as PDF/X-1a. With 1 profile, 1 color space only. – So, obviously it works both.

[Shoku]

6 hours ago, thomaso said:

Yes. This is as it may and should be.

Whereas in the screenshot above you see the same .afpub as PDF/X-1a. With 1 profile, 1 color space only. – So, obviously it works both.

It may have one profile -  the CMYK output Intent - but it also has multiple color spaces, so they were not converted to CMYK.

[MikeW]

That image shows a single, ICC tagged RGB image. This is as it ought to be for a late-binding work-flow when using a PDF profile that allows it.

[thomaso]

@Shoku, these of your posts sound contradictory to me – or I might misinterpret them:

On 5/18/2019 at 6:59 PM, Shoku said:

IN PDF/X assigning a CMYK profile to the document removes profiles embedded in any images.

11 hours ago, Shoku said:

It may have one profile -  the CMYK output Intent - but it also has multiple color spaces, so they were not converted to CMYK.

What do you want to achieve? Is it ...

– either to keep all original color spaces and/or profiles
– or to get converted all of them to 1 only?

– Or is it not about export but resources' color space/profile handling as offered in "Document Setup":

In that case I am lost. To me it appears those buttons don't do anything and always get auto-set in the UI to "Convert" after closing that window, – whereas on export instead "Assign" seems to be used.

 

[phph]

Hi thomaso and everyone who replied!

Thank you for your replies!

Returning to your first message, @thomaso:

21 hours ago, thomaso said:

I don't get an error message when exporting to X-1a with ISO Coated v2 300% (ECI) .
Also the result looks fine for preflight, see screenhot:

Just to be sure: Which preflight profile did you use that did not return an error?

We get the error ("Output Intent not suitable for printing (unknown ICC profile) (V2.4)") with the preflight profile PDFX-ready Sheetfed Offset Classic HQ V1.5.

As I said: The PDF looks fine for printing. So this is mostly a question of complying to our workflow. But we would like to get to the bottom of the question, whether the fault lies with the preflight profile or in the way Affinity Publisher writes ICC profiles into the PDF.

[phph]

Hi everyone

As we’re still experiencing the failure of the preflight check in Adobe Acrobat even with the latest Publisher beta:

Has anyone been able to export a PDF-X1a with a profile such as ISO Coated v2 that passes the preflight profile PDFX-ready Sheetfed Offset Classic HQ V1.5.? We continue to get the error

Quote

Output Intent not suitable for printing (unknown ICC profile) (V2.4)

Thanks for any input!

[maxgrafik]

Exact same problem here since the first beta. So at least this behaviour is consistent

I guess as long as ICC profiles written by Publisher have the "wrong" MD5 checksum the preflight will fail. You could add the wrong checksum to your preflight profile so it stops complaining. However, your printshop may still complain then.

[3joern]

Any news on this topic? Publisher now has a preflight (checklist). After a long test phase, I would like to use Publisher in a productive environment for a book production, but I am worried that the still somewhat unreliable colour management will blow up in my face (sorry Affinity, if I create a cmyk document and I have 100% black in the font and select a different colour profile when exporting the PDF, the black font is converted to 4c, which does not inspire confidence).

Do you have any tips on what I should look out for in the publisher, which was of course no problem before with Indesign?

[Old Bruce]

8 hours ago, 3joern said:

(sorry Affinity, if I create a cmyk document and I have 100% black in the font and select a different colour profile when exporting the PDF, the black font is converted to 4c, which does not inspire confidence).

Wouldn't have believed this but, wow it is true. The Paragraph Styles need to be reapplied for the colour to go back to 0 0 0 100.

Should not have to do that reapply.

[MikeW]

59 minutes ago, Old Bruce said:

Wouldn't have believed this but, wow it is true. The Paragraph Styles need to be reapplied for the colour to go back to 0 0 0 100.

Should not have to do that reapply.

Which is one reason why a layout application should be color agnostic. But, I'm sounding like a broken record...

[asterix]

is there any news about this behaviour (see first posting above) ?

I also get this warning/error in the preflight in Acrobat with PDF/X profiles. Are the ICC profiles changed in Affinity (in my case Designer) while exporting a PDF/X so that the preflight can't approve that it's the correct ICC?

(it's still there in V2 so perhaps it's better to open a new topic for V2)

Edited May 26 by asterix