Affinity Publisher changes black text to CMYK colour in PDF/X-4 files!

[karipu]

My printing house demands printing files as PDF/X-4 files but when exporting from the Affinity Publisher it changes black text to CMYK colour!

How could I avoid this bug or is there a way to fix PDF files?

[lacerto]

There are many ways this could be happening inadvertently. If you can post an example, along with information on your document color mode and the way black text is defined, it helps to narrow down possible causes.

But basically:

1) Make sure that your document is in CMYK/8 color mode and that it has the document color profile requested by your printer defined as the document color profile.

2) Make sure that you have all text defined in K100 (and C, M and Y = 0).

3) When exporting, use "Document color mode" and "Document color profile" (= Do not pick at export time a color profile that deviates from the defined document color profile, because this causes export time color conversions, including K100 text becoming four-color black).

4) Make sure that you have not any other than PDF/X-4 based PDFs placed in the document. Affinity apps force rasterization of those kinds of PDF files, causing K elements becoming four-color black.

UPDATE: Here is a Publisher file demonstrating the first three points.

pdfx4_blacktest.afpub

[karipu]

OK, thank you for your information!

[JeremyTankard]

Hi. I've followed the above but all my PDFs for print have CMYK black.

(using Pub 2.6.2)

[lacerto]

18 minutes ago, JeremyTankard said:

Hi. I've followed the above but all my PDFs for print have CMYK black.

Can you post a one-page sample where this happens?

[JeremyTankard]

@lacerto – could you screen grab your settings for colour, document colour and exprt to PDF so I can replicate – thanks

How do you get black text printed on a colour (CMY) not to drop out to white but overprint?

[lacerto]

1) Setting up the document color mode and profile (pick the one recommended by the printer already here, do not change at export time):

2) Define text that you want to be K100 (on black plate only) using CMYK (not Grayscale, which in Affinity apps would produce four-color-black in CMYK output):

3) When exporting, make sure that the export color mode and color profile match the document color mode and profile. You can specify the Color mode either "As document" or explicitly as "CMYK", the color profile as "Document color profile" or explicitly the same that you used in stage 1 when you specified document color profile (note that if you change the document color profile at a later stage, you need to choose the "Assign" mode if you do not want the colors of the document recalculated; allowing recalculation (Conversion mode) would e.g. cause changing of K100 definitions to four-color black; if the color profile change is significant, you just need to allow recalculation but then need to Find and Replace the rich blacks and change them back to K-100; changing the color profile at export time always results in recalculation of color definitions and K100 turning to rich black). If you use specifically PDF/X-4 method, these options are automatically selected as defaults, as shown below:

Note that "Overprint black" is also selected. This defines that K100 blacks have overprint attribute automatically turned on, which means that K100 does not knock out underlying CMY values -- note that already K99 does, so if you want to have more specific overprinting, or have blacks (or other colors) that alternately knock out or overprint, you need to specify swatch color values and give them the overprint attribute as needed. The video below and the attached Publisher document demonstrate this, too.

Notice, too, that "Convert image color spaces" is not checked by default when using PDF/X-4 mode because this method (as basically any other than PDF/X-1a:2003, within Affinity apps) allow mixed color spaces (e.g. photos left in RGB color space). PDF/X-4 also has ICC profiles embedded and you cannot change this setting (when having mixed color spaces, ICCs need to be included to have proper color processing when the document is RIPped).

pdfx4_overprint.afpub

 

[werfox]

@lacerto: I have been following your distinct explanations of the correct CMYK workflow and its perils with the Affinity applications for some time now.
I think the manual posted above should be in the Affinity Publisher help files!

Or you could collaborate with @MikeTO with his also excellent manual!

Hats off to both of you!

 

Best regards

[JeremyTankard]

Excellent, thanks so much!