Export PDF/X 1a with CMYK Color Profile does not what expected

[Oliver551]

I created a Affinity Photo document with color format CMYK/8 and profile "ISO coated V2 (ECI)" which should go to a print service.

My problem: The export "PDF (for print)" shows the colors similar to the document in Affinity Photo, but the export "PDF/X-1a:2003" is much darker - both with the mentioned profile embedded. Darker means in a PDF viewer as well as printed out.

I tried many things, different CMYK profiles, a very simple document, same result.

I analyzed the exported PDFs (with Acrobat preflight) and found a remarkable difference:

• PDF/X-1a
  • Color space: DeviceCMYK
  • Output intend: ISO Coated V2 (ECI)
  • => Colors darker
• PDF (for print) - generates "Standard PDF 1.7"
  • Color space ISO Coated V2 (ECI)
  • Output intend: None
  • => Correct colors (similar to Affinity Photo)

I would expect the same result for "Color space" and "Output intend" for both PDF types, I think Affinity Photo does the correct work with "PDF 1.7", at least it's what I would expect. I guess the additional translation from (wrong) profile DeviceCMYK to ISO Coated V2 (ECI) causes the different colors - all objects in the document are already ISO Coated V2 (ECI).

Am I wrong or is it a bug?

Best regards, Oliver

 

[Dan C]

Hi Oliver551,

Welcome to the forums

Could you please provide a copy of your .afphoto file along with the exported PDFs to the following link so I can investigate this further for you? I'm not 100% certain what's happening here without seeing the documents, apologies!

https://www.dropbox.com/request/ncA1wYQkkAGBkPF6QJjR

[SrPx]

Could  be that DeviceCMYK is the one from the preferences/Colour CMYK profile ? (ie, picking it from there instead of the document profile ?  maybe trying to set there your ISO profile, see if it works ?  (very random idea)

[Oliver551]

Hi Dan,

I uploaded a test case into Dropbox, thank you for your help.

Best regards, Oliver

 

[Oliver551]

Hi SrPx,

The default CMYK color profile in preferences is set to "ISO Coated V2 (ISO), to be sure I also converted the whole document to this profile. But does not help ...

Best rregards, Oliver

[Dan C]

Thanks for that, when exporting to PDF/X 1a, the colour profile is not embedded as instead it's written to the file as 'rendering intent'. This is the correct behaviour and the same can be seen from other design apps.

This has been discussed previously on the forums below - 

Your printer at home likely cannot deal with 'rendering intent', which is why your PDF is printing as dark as it appears in the PDF viewer, however a more sophisticated printer that can handle this will print your document correctly.

You can check the correct profile has been set in a preflight check of your document, as below - 

[Oliver551]

Hi Dan,

thank you for investigating this issue. The PDF/X 1a document not only prints darker, the same happens in the PDF viewer.

Ok, I'm fine with profiles not being embedded, everyone can download them anyway. BUT why are all objects in the PDF file declared as color space "Device CMYK" although I converted all objects in Affinity Photo to "ISO Coated V2"? (I checked every single object in this PDF)

Output will be converted to rendering intent which in this case changes the colors since the color profile definitions for source (objects in PDF) and destination (output device) are different. This shouldn't be the case since ALL PDF objects were created with color space "ISO Coated V2".

Best regards, Oliver

[Dan C]

No problem at all

18 hours ago, Oliver551 said:

The PDF/X 1a document not only prints darker, the same happens in the PDF viewer.

If you are using a different CMYK display profile than ISO Coated v2 (ECI) then the PDF will appear differently after export, as Designer is implementing colour transformation in-app.

Unless your printer supports 'output intent' then PDF/X Documents will NOT print correctly. 

18 hours ago, Oliver551 said:

why are all objects in the PDF file declared as color space "Device CMYK" although I converted all objects in Affinity Photo to "ISO Coated V2"?

When exporting to PDF/X-1a document content is colour transformed to the Export Profile during the export, and we inform the PDF consumer we have done so by specifying the Export Profile as the Output Intent in the PDF.

Since the colour content has already been transformed during export, setting each individual object's Colour Space to ‘DeviceCMYK’ is the correct thing to do because no further colour transformation is desired / necessary.