APub: Please (weeping) help with the PDF CMYK Debacle

[Mike W077]

OK, here's the deal. Whenever I "place" anything created outside Affinity Publisher into Affinity Publisher, and then export the publication to PDF for CMYK printing, APub changes the CMYK values in the placed file!

I have tried placing PDF files and Affinity Designer files, always the same result. I have tried every setting I can think of under preferences and PDF export that I can find. I don't want this! Why does it do this? I want to stay with APub, but this issue has me and our publishing company back with InDesign. 

I export to PDF from Designer, color values remain correct. I import the same file to APub, then export the page to PDF, the color values have changed! This is especially vexing with 100% black, which ALWAYS gets changed to a combination of CMYK values. My printer can't work with this. 

However, if I fill a square with 100% black in APub, then export to PDF, the color value remains 100% black. Argh! But, if I import a PDF or a native Designer file, then export the page to PDF from APub, I get a mix of CMYK values instead of 100% black. Argh again!

This CANNOT be right. There HAS to be a simple switch fix for this. Surely SOMEBODY out there has solved this. Please help! 

Thank you in advance. 

[thomaso]

The 'easiest' would be to avoid colour conversion between APub and placed document and export, by setting both files, .afpub and afdesign, to the same colour space & profile and export with this profile "As document" (in Export > More > … ).

[lacerto]

My experience when placing AD content using the same color profile is similar, so color definitions should be retained, at least when not using complex adjustments (I cannot say whether they would be applied similarly as when applied to native Publisher objects or when used in Designer and resolved, or exported from, there). But PDFs placed for passthrough is a completely different and more complex story.

There the rule of thumb is that you cannot use PDF/X-based export methods with PDF content that is created with non-PDF/X  based methods, and have it passed through. Instead, this content will always be rasterized and with incorrect color values. So whenever placing PDFs to be passed through and they are not PDF/X-based, export using "PDF (press-ready)", which uses PDF v.1.7. When using PDF/X-based export method, all PDF content to be passed through must be PDF/X-based and produced with the same or minor PDF version number, except when using PDF/X-1a:2003, which will rasterize all placed PDF-content.

As for reading color values, it should be noted that if the design contains any transparency, Affinity apps typically apply sRGB blending space to transparency groups which confuses at least Adobe Acrobat Pro. It certainly confuses most users, prepress personnel included, and I am not sure if it would confuse RIP, as well, resulting in getting wrong colors on paper.

The following clip demonstrates the complexity that using an RGB blending space applied to CMYK objects causes for interpreting color definitions of an Affinity produced PDF file. It was exported using the default PDF 1.7 "PDF (press-ready)" preset that embeds the document ICC. Not embedding the document ICC makes initial reading of color values in Adobe Acrobat Pro a bit less confusing because the simulation profile does not need to be matched with the document profile, but it does not resolve the problem related to mixing RGB and CMYK color modes in transparency groups. In the end, the video shows how a PDF 1.7 exported from InDesign with default settings, with placed Publisher created PDF files, uses DeviceCMYK blending space for the transparency group and shows correct color values in Output preview no matter which simulation profile is used (that's because all color involved operations, including transparency blend space are DeviceCMYK and not dependent on profile-based calculations). 

Note that if you place Designer content in a Publisher file (or any Affinity file) and it uses different color profile, all color values are recalculated so e.g. CMYK values won't be just passed through. Passing through is only supported in placed PDF content, and there, too, in a very limiting way. Note too that placed Designer content will have their native color profiles applied, while placed non-Designer files that are interpreted (e.g. AI files, PDF placed for interpretation, EPS files), will have the profile assignment done according to the setting in Preferences > Color.

 

[Mike W077]

On 5/12/2023 at 7:31 PM, thomaso said:

The 'easiest' would be to avoid colour conversion between APub and placed document and export, by setting both files, .afpub and afdesign, to the same colour space & profile and export with this profile "As document" (in Export > More > … ).

Thank you for the replies. I will try the suggestions (away from the office at the moment). But, bottom line, no one so far knows a straightforward fix. Hmmm. InDesign just leaves the values the same when exporting placed CMYK PDF content to InDesign PDF. APub changes them. If one of these works, at least we could work them into our work flow. 

[manfred.schmid]

affinity publisher is just the worst offender when it comes to placed pdf documents. i would recommend, if possible, converting all pdfs to eps documents or us the action "convert all fonts to outline" in acrobat pro and then place those pdfs as interpreted. 

passthrough is just not working with any pdf besides publishers own. specially adobe pdf exports don't work in publisher. 

just outline fonts in acrobat and then interpret the placed pdf is the best option, highly recommended, all colors as expected, no errors.

downside, you will need to purchase a full license for acrobat pro

 

[manfred.schmid]

just in case you are wondering: nothing helps that situation,

1) pdf/x output intent set to same as publisher document - wrong colors on passthrough

2) every single element tagged with same profile as the publisher document - wrong colors on passthrough

3) complete pdf decalibrated and all elements set as device cmyk - wrong colors on passthrough

[lacerto]

Your problems are probably caused by having non-PDF/X-based or PDF/X-1a-based PDFs placed for passthrough, and exporting using any PDF/X method. These kinds exports are typically rasterized by Affinity apps. If you have non-PDF/X-based placed PDFs that you want to pass through, the best choice to succeed is choosing "PDF (press-ready)" that by default uses PDF version 1.7, convert color spaces to CMYK, and deselect profile embedding. This will create a Device-CMYK PDF with native color values and original fonts embedded, and respects overprint attributes, etc. [EDIT: and passes through all kinds of PDFs]. If your placed PDFs are all PDF/X-based [EDIT: and you need to use PDF/X-based export method], you should choose PDF/X-4, to make sure that export PDF uses the same or later PDF version as placed PDFs. 

Converting to EPS might work, but then it is good to know that overprint attributes are not honored, and spot colors are not supported. These are Affinity-specific limitations (and fonts left embedded would automatically be converted to curves, too). Letting Affinity interpret placed PDFs, especially if fonts have been converted to outlines, might work, but then you need to pay attention to possible color profile conflicts, because interpreted (CMYK) PDFs will be assigned the working color (CMYK) profile, not the document color profile (and never discarded and just passed through, as by default happens when working with Adobe apps). And if there is a profile conflict at export time, all CMYK color values will be recalculated (causing e.g. K100 blacks becoming four-color blacks).

[manfred.schmid]

pdfs are all pdf/x-4 compliant, publisher just does whatever no matter what. passthrough just doesn't work!

[lacerto]

An example would be nice!

In my rather superficial and schematic tests PDF/X-4 files placed for passthrough generally behave well in a sense that they are not rasterized and their native colors are passed through when exported from an Affinity app (disregarding the app that initially created these files). On the other hand, I have noticed that multiple PDFs (including PDF/X-4, and ones created solely by Affinity apps) do not seem to interact expectedly with each other e.g. in Adobe Acrobat Output Preview or Packzview, meaning e.g. that overprint and blend mode attributes are not correctly rendered nor calculated, even if the attributes themselves appear to be exported. This means that the actual effects on paper of complex jobs placed on top of each other or on colored background are utterly hard if not impossible to predict. RIPped proofs (if not printed ones) would be the only way to ensure expected output.

Attached are PDF/X-4 exports made  by Affinity Publisher 2.4.0 and InDesign CS6 using the same components, and only the export created by InDesign shows effects of interactions of all involved files when using tools like Adobe Acrobat Pro 2020 and Packzview.

multiplepdfx4_apub.pdf

multiplepdfx4_id.pdf

 

[Jane DK]

On 5/15/2023 at 9:22 PM, Mike W077 said:

Thank you for the replies. I will try the suggestions (away from the office at the moment). But, bottom line, no one so far knows a straightforward fix. Hmmm. InDesign just leaves the values the same when exporting placed CMYK PDF content to InDesign PDF. APub changes them. If one of these works, at least we could work them into our work flow. 

 

On 5/13/2023 at 1:00 AM, Mike W077 said:

OK, here's the deal. Whenever I "place" anything created outside Affinity Publisher into Affinity Publisher, and then export the publication to PDF for CMYK printing, APub changes the CMYK values in the placed file!

I have tried placing PDF files and Affinity Designer files, always the same result. I have tried every setting I can think of under preferences and PDF export that I can find. I don't want this! Why does it do this? I want to stay with APub, but this issue has me and our publishing company back with InDesign. 

I export to PDF from Designer, color values remain correct. I import the same file to APub, then export the page to PDF, the color values have changed! This is especially vexing with 100% black, which ALWAYS gets changed to a combination of CMYK values. My printer can't work with this. 

However, if I fill a square with 100% black in APub, then export to PDF, the color value remains 100% black. Argh! But, if I import a PDF or a native Designer file, then export the page to PDF from APub, I get a mix of CMYK values instead of 100% black. Argh again!

This CANNOT be right. There HAS to be a simple switch fix for this. Surely SOMEBODY out there has solved this. Please help! 

Thank you in advance. 

I could have written this myself! I was just thinking I might be the only one on the planet standing back, nervously bewildered and struggling to decode sheets og technical jargon from well meaning experts when all I want is to know which boxes to check and which to leave unchecked (as with InDesign). I am not averse to a simple workaround when tools from 2 different programmes don't quite correspond - but I draw the line at converting the entire text to curves in order to maintain 100k in the exported pdf. (I produce a 24 page newspaper). I do hope you are still on this forum - and I really hope you will be writing back to tell me that you cracked it in the end!

Best regards

Jane