Overprint is Not Honoured in Non PDF/X Compliant PDF Files When Exporting Placed PDF Files Using PDF Passthrough

[Hangman]

Exporting placed PDF files using PDF Passthrough will correctly honour Overprint for PDF/X compliant files but ignores Overprint for non-PDF/X compliant files (i.e., PDF 1.4, 1.5, 1.6 and 1.7).

Exporting placed PDF files using PDF Interpret ignores Overprint for both PDF/X compliant and non-PDF/X compliant files, i.e., all PDF Formats.

07. pdf_1.7_passthrough_export.pdf

07. pdf_1.7_interpret_export.pdf

 

[NathanC]

Hi @Hangman,

Just focusing on passthrough, I've created a PDF file containing a single spot colour on a rectangle set to overprint and then exported it to v1.7, I've then placed that PDF on a new Pub document with it set to passthrough and then exported that pub document to PDF 1.7, after opening the file in Acrobat I can see that my spot colour has been retained and the overprint on the object inspector shows as 'True'.

For comparison, I also opened up your 1.7 passthrough PDF and checked each page with the object inspector on output preview, the overprint value shows as True for all Non PDF-X pages on the Pantone spot colours along with the 3 colours labelled 'Overprint'.

It doesn't look like it's possible to retain the overprint property on Interpreted PDFs despite spot colours being retained, i'll have to check internally if this is possible or needs logging.

With the Passthrough PDFs, have I missed/overlooked something?

 

 

Placed 1.7 Passthrough PDF.pdf Pub document containing placed 1.7 PDF.afpub

[Hangman]

Hi @NathanC,

Apologies for the delayed reply, I needed to check a couple of things first...

So, the confusion I think was created for two reasons...

1. For some reason, non-PDF/X compliant PDF files created using Affinity software that uses Overprint do not show the Overprint when viewed in Acrobat Reader even when Use Overprint Preview is enabled.
    
2. Because of this, I use PDF Reader software that does correctly show the Overprint for, Affinity-generated, non-PDF/X compliant PDF files.

However, when placing all PDF versions (PDF 1.4, X-1a, X-3, 1.5, 1.6, X-4 and 1.7) in a Publisher document using PDF Passthrough and then exporting to all PDF versions, the PDF Reader that correctly shows Overprint for, Affinity-generated, non-PDF/X compliant PDF files, no longer shows the Overprint, though it turns out, this may be a bug, hence the initial confusion.

The same is also true for all PDF variants, including PDF/X when exporting PDF files placed in Publisher using Interpret.

The questions therefore become...

1. Why don't non-PDF/X compliant PDF files created in Affinity apps show Overprint Preview in Acrobat Reader (and possibly Acrobat Pro, though I'm unsure if this is also the case), when non-PDF/X compliant PDF files created in other apps do show Overprint Preview?
    
2. Why do both PDF/X and non-PDF/X compliant PDF files, placed in Affinity apps using PDF Interpret and exported using all variants of PDF not show Overprint Preview in Acrobat Reader or other PDF Readers?

[NathanC]

Hi @Hangman,

19 hours ago, Hangman said:

Why don't non-PDF/X compliant PDF files created in Affinity apps show Overprint Preview in Acrobat Reader (and possibly Acrobat Pro, though I'm unsure if this is also the case), when non-PDF/X compliant PDF files created in other apps do show Overprint Preview?

For my screenshots/examples I've used Acrobat Pro's Output Preview tool which is showing the overprint value as expected on non PDF/X placed files. I'm pretty sure the Output Preview tool is only available in the full version rather than the free version of Acrobat (if there is another way to check this, let me know). Which other PDF reader app(s) are you using to check the overprint preview for comparison?

19 hours ago, Hangman said:

Why do both PDF/X and non-PDF/X compliant PDF files, placed in Affinity apps using PDF Interpret and exported using all variants of PDF not show Overprint Preview in Acrobat Reader or other PDF Readers?

I'll raise this internally and come back to you on this one, as it currently looks like a object property which isn't interpreted.

[Hangman]

Hi @NathanC,

37 minutes ago, NathanC said:

I'm pretty sure the Output Preview tool is only available in the full version rather than the free version of Acrobat (if there is another way to check this, let me know).

There is an option in the Acrobat Reader Preferences, under Page Display, where you can turn 'Use Overprint Preview' on (it is off by default). When it's set to 'Always' it displays the Overprint but only for PDF/X files. Note that there is also a PDF/X Only option but 'Always' should display Overprint for non-PDF/X files as well (see attached file).

07. pdf_1.7_passthrough_export_nep.pdf

If you then take a look at this PDF 1.7 file in Acrobat Reader when 'Use Overprint Preview' is set to 'Always', you will see the Overprint is correctly displayed.

PDF_1.7_Overprint_Test_Hybrid.pdf

It appears that there is something preventing Affinity generated non PDF/X files from correctly displaying Overprint.

37 minutes ago, NathanC said:

Which other PDF reader app(s) are you using to check the overprint preview for comparison?

I've tried PackZView, Callas PDFToolBox, Foxit PDF Reader and FlighCheck 2023. Interestingly, FoxitPDF Reader has a 'Simulate Overprinting' option in the Print dialog window which does correctly 'simulate' the overprint for Affinity-generated, non-PDF/X files., however, it's still missing for Affinity-generated Interpreted PDF files.

The issue is that non-PDF/X files created in other applications where Overprint is used do correctly show the Overprint in Acrobat Reader and other PDF Readers.

I don't currently have access to InDesign or Illustrator but I'm sure a quick simple could be created in both InDesign and Publisher using Overprint and likewise, then both Placed using Passthrough and Interpet, exported to PDF 1.7 and then opened both in Acrobat Reader for comparison.

Also, looking at the individual separations for the non-PDF/X files, the overprint doesn't look right... I'll see if I can provide an example shortly.

37 minutes ago, NathanC said:

I'll raise this internally and come back to you on this one, as it currently looks like a object property which isn't interpreted.

Okay, thank you, that would be really helpful, I'd be very interested to understand if that is the case and if it can be fixed.

 

[NathanC]

Thanks for the additional detail and clarification, I'm seeing exactly what you mean after changing the 'Use Overprint Preview' setting in Acrobat to 'Always' and ignoring the Output Preview tool, only the  Passthrough PDF/X files actually show an overprint preview on the canvas, while non PDF-X documents appear to have no overprint.

In my original post I was too focused on the Object Inspector tool to assess this rather than the page content which interestingly does show that the three objects are set to overprint (Overprint= 'True'), it just fails to show this on the page content. If I just open one of non PDF-X documents directly in acrobat without placing it in another doc, the overprint preview shows correctly.

I'll do some more digging and get back to you on this, as it does look like a bug.

1 hour ago, Hangman said:

2 hours ago, NathanC said:

I'll raise this internally and come back to you on this one, as it currently looks like a object property which isn't interpreted.

Okay, thank you, that would be really helpful, I'd be very interested to understand if that is the case and if it can be fixed.

I've since confirmed with QA that this needs logging and have now logged it with the developers, particularly since it can maintain the Spot colours on Interpret. 🙂

[Hangman]

Hi @NathanC,

Many thanks for the update and for confirming that both issues appear to be bugs and for logging...