Headache with color management (v2)

[entropy]

I'm struggling to understang how to properly manage color in cmyk pdf export with affinity products.

Why as my document (publisher) is in cymk with "convert" selected, when I export to pdf for print some of my images are still in RGB ?

And why, In my CYMK document when I export to pdf (with the same profil), my 0 0 0 100 blacks are converted to 85 72 62 94 ?

I'm never able to get my pdf properly generated, there is always something messed up with colors.

[Vosje]

Did you try PDF/X as export? This whole color management also gives me a headache but I have read somewhere that PDF/X usually gives a consistent result with correct color settings...

[thomaso]

2 hours ago, entropy said:

Why as my document (publisher) is in cymk with "convert" selected, when I export to pdf for print some of my images are still in RGB ?

Have you tried to modify a default Affinity export preset by activating the option "Convert image colour spaces" (and de-activating "Embed Profiles")?

2 hours ago, entropy said:

And why, In my CYMK document when I export to pdf (with the same profil), my 0 0 0 100 blacks are converted to 85 72 62 94 ?

Where did you check the exported black definition? Even if document profile + export profile are the same the app that opens a PDF may use a different profile. Thus the hint of @Vosje works as workaround since PDF/X includes an "Output Intent" that has to get respected by a PDF viewer according to the PDF/X specification.

[entropy]

2 hours ago, Vosje said:

Did you try PDF/X as export? This whole color management also gives me a headache but I have read somewhere that PDF/X usually gives a consistent result with correct color settings...

Yep, PDF/X-1a does not allow rgb so it's ok, but I feel like I have no control when it comes to color conversion, or ink coverage control.

 

22 minutes ago, thomaso said:

Have you tried to modify a default Affinity export preset by activating the option "Convert image colour spaces" (and de-activating "Embed Profiles")?

Where did you check the exported black definition? Even if document profile + export profile are the same the app that opens a PDF may use a different profile. Thus the hint of @Vosje works as workaround since PDF/X includes an "Output Intent" that has to get respected by a PDF viewer according to the PDF/X specification.

Yep, I know that ICC embed profil messes up with pdf preview (like FF or Edge built in pdf reader)

I open my document in photo, (CYMK mode). When I had the pro version of acrobat I could check directly with the built-in tools

But something I don't understand is why if my color space document is CYMK, when i export to pdf (ISO coated V2 300% for exemple, convert color space checked). Colors are f***ed up.

Like :
0 0 0 100 -> 69 60 58 82
30 30 30 100 -> 70 64 61 88
100 100 100 100 -> 73 66 66 95

Why, 100% black is converted to CYMK black ? Or 30 30 30 100 to 70 64 61 88 ?

It's very tricky especially when you work with black and white( and when you want rich black and 100% black).

Also I can't figure out how to control ink coverage.

[thomaso]

23 minutes ago, entropy said:

I open my document in photo,

What document profile does the opened PDF show in APh? I guess it gets opened with your default cmyk profile set in APh's preferences – are they all 3 the same (creation > export > import)?

[Vosje]

32 minutes ago, entropy said:

Also I can't figure out how to control ink coverage.

Yeah, this drives me nuts that there's no preflight option that lets you see color separations... 😣

[thomaso]

37 minutes ago, entropy said:

Also I can't figure out how to control ink coverage.

You could use the same workaround: open the PDF in APhoto and check the darkest areas with the pipette.

While I'd assume the workflow / layout would give hints to the total ink coverage even before export.