Importing PDF Text into CMYK Document in Designer

[rzolau]

I have a text-only PDF in CMYK (the entire text uses the K chanel only and is C:0,M:0,Y:0,K:0.75, the PDF has DeviceCMYK space). Now, I am importing this PDF into my document in AD 1.10.8 (under macOS I am dragging it from Finder into the target artboard). My AD dcument has CMYK/8 colorspace with "Convert" option turned on (also my prefered color profile assigned). The PDF imports fine in the sense that the text (glyphs), kern, line breaks, fonts and so on are recognized correctly. However, the imported text instead of being "K only" uses full CMYK colors (as if it was imported as RGB). This is problematic as each time I import I have to correct the color. Any suggestion how to "force" AD to preserve CMYK colors from the PDF?

Another question: as I mentioned, the text imports fine (almost perfectly). However, by default AD enables ligatures and contextual alternates (even though they are not enabled in the PDF). Is there a way to have them disabled by default? Again, I have to select the imported text and then disable them via Character/Typography tab.

 

Thank you!

[Hangman]

4 hours ago, rzolau said:

I have a text-only PDF in CMYK (the entire text uses the K chanel only and is C:0,M:0,Y:0,K:0.75, the PDF has DeviceCMYK space). Now, I am importing this PDF into my document in AD 1.10.8 (under macOS I am dragging it from Finder into the target artboard). My AD dcument has CMYK/8 colorspace with "Convert" option turned on (also my prefered color profile assigned). The PDF imports fine in the sense that the text (glyphs), kern, line breaks, fonts and so on are recognized correctly. However, the imported text instead of being "K only" uses full CMYK colors (as if it was imported as RGB). This is problematic as each time I import I have to correct the color. Any suggestion how to "force" AD to preserve CMYK colors from the PDF?

If the PDF uses Device CMYK then the colour values should be maintained when opened or placed and then edited. Are you able to upload the PDF file so we can take a closer look?

Which colour profile does your AD document use?

5 hours ago, rzolau said:

Another question: as I mentioned, the text imports fine (almost perfectly). However, by default AD enables ligatures and contextual alternates (even though they are not enabled in the PDF). Is there a way to have them disabled by default? Again, I have to select the imported text and then disable them via Character/Typography tab.

I'm not aware of any way to disable these by default, even when ligatures and contextual alternates are disabled in the source file they appear to be enabled when opening the PDF for editing purposes. If Placed using Passthrough then the ligature state is honoured as expected.

[lacerto]

5 hours ago, rzolau said:

This is problematic as each time I import I have to correct the color. Any suggestion how to "force" AD to preserve CMYK colors from the PDF?

Hi @rzolau, and welcom to the forums.

You mention that you drag and drop your PDFs onto a Designer artboard. This is equivalent to using File > Place, and using the default placement mode, which is "Passthrough". Please check that this mode is shown on the context toolbar when you have the placed PDF selected.

On the other hand, you also mention that you can select the "imported" text, specify formats like ligatures, etc., and this implies that instead of placing the document, you have actually opened a PDF for editing? It is crucial to know which way you have your DeviceCMYK PDF brought in Designer, since the advises vary depending on what you have done.

Also, please ensure that you are viewing the resulting PDF with an app that does not show recalculated color values. E.g. Adobe Acrobat Pro might use a simulation based on target ICC profile and show translated color values, in case the viewed PDF has embedded ICC target, and in this case the simulation profile must match the embedded target profile.

As for your second question, if it is a document that has been placed for passthrough, all native formatting is retained and whatever you have active in the hosting document, only applies to text that you have created in that document. As for interpreted or opened PDF, I would assume that formatting of the source document is used, but I have not examined this thoroughly, and know that certain settings, like overprinting attribute, is not correctly read by Affinity apps, so there is point in checking all these kinds of formats when not just placing for passthrough.

[rzolau]

Thank you -- this is extremely useful and got me on the right track! I will report more soon (as soon as I get to my home office and be able to do more tests). In short, I think the entire issue is due to how drug-n-drop works in my multi-computer setup. Something I did not mention earlier: the PDF is generated on one macOS machine and then I drag-n-drop it to AD running on another (different) macOS machine. I am essentially using the macOS Universal Control, which clearly must be either messing up the document I am dragging or is confusing the AD import feature (the PDF seems to be indeed opened for editing instead of being placed, e.g., I do not see "Embeded document" menu and the "PDF Passthrough" selector the way I now realize it should appear).

[rzolau]

OK, so to add to what I wrote (perhaps someone may find it useful): indeed the culprit is the macOS Universal Conrol -- disabling it has the desired effect of PDF being embeded, and I can choose which PDF passthrough mode to use. Now interestingly, what see is that: if I select "Passthrough" then ligatures, etc. are preserved as in the original PDF, however the color is still not CMYK (my AD document is set to CMYK/8 and I use CMYK sliders and the color picker to check the CMYK values of the font). If I select "Interpret", then I am getting correct CMYK value for the font, BUT, ligatures get enabled and there seems to be no way to disable them. Moreover, the "Interpret" seems to be ignoring whatever defaults I saved for the "Typography" tab (I am ceating new document, then I am setting Typography options and finally I go "Edit->Defaults->Save".

In summary, I can either have disabled ligatures or properfy set the text color but not both 😞

Again, any help will be much appreciated...

Edited February 29 by rzolau

[lacerto]

On 3/1/2024 at 1:11 AM, rzolau said:

indeed the culprit is the macOS Universal Conrol -- disabling it has the desired effect of PDF being embeded, and I can choose which PDF passthrough mode to use

Thanks for sharing, this is odd, but good to know.

Basically you should just use the Passthrough mode if you want to retain all features of the original file. Just remember the so called "PDF compatibility rules" that are in force within Affinity apps, so that placed content will not be rasterized.

Note that when you have Passthrough mode, the shown content is rasterized on display so you cannot use the color picker to verify the color values of placed content. You need to export the PDF and then examine the color values to make sure that the native values have been retained.

EDIT: Note too, that the color picker always shows color values in document color mode so in case your document color mode is RGB, you would see K75 values of an interpreted PDF converted to RGB, according to your current profile environment. 

Attached is a DeviceCMYK K75 dummy PDF, which was placed in a Designer 1.x document as passed through and then exported, and the original color values are retained.

devicecmyk75.pdf

devicecmyk75_placed_exported.pdf

PS. What you mention about ligatures and OpenType features in interpretation mode is interesting, I'll check the behavior.

[rzolau]

Thank you again! The comment about resterization in the passthrough mode makes some sens, although I would still expect color picker to act as expected. For example, if I place an 8-bit grayscale TIFF in the same document, the color picker shows CMYK values (only K-channel utilized) the way I would expect. Is it because without the interpretation AD assumes the deafult DeviceRGB (especially that both can be used at the same time in PDF)?

Anyway, still trying to find a workaround to the ligatures hickup 🙂

[thomaso]

1 hour ago, rzolau said:

I would still expect color picker to act as expected. For example, if I place an 8-bit grayscale TIFF in the same document, the color picker shows CMYK values (only K-channel utilized) the way I would expect.

Unfortunately the Picker Tool can show only one colour mode, as @lacerto mentioned it is the colour space of the document.

If you place a grayscale image in a CMYK document then the button "K Only" gets automatically activated which results in only K values for the Picker Tool. If you deselect 'K Only' in the Context Toolbar for this image then the Colour Picker shows the gray in 4 ink channels. – Additionally, if you have 'K Only' for a grayscale image deactivated in a CMYK document then it will be exported in 4-channel gray even if the image resource was saved with a grayscale profile. This is related to the fact that Affinity handles grayscale colours internally as RGB/HSL, even in a CMYK or grayscale document.

The Colour Picker limitation to the current document colour mode also means that it shows colours of an RGB resource in a CMYK document as CMYK values.

Affinity's 'K Only' workflow (or workaround) also means you can activate 'K Only' for an RGB resource to get it exported as K values only. If you apply a fill colour to an RGB image with 'K Only' activated it gets applied accordingly to its K only equivalent and thus appears monochromatic and brighter, different to the fill colour applied to an RGB resource without 'K Only' pressed.

[rzolau]

Ha, that explains everything! Thank you!

[lacerto]

6 hours ago, rzolau said:

Ha, that explains everything!

No, it is still more complex 🙂

When having a PDF placed in interpreted mode, a placed PDF with DeviceCMYK colors (no profiles embedded) will get assigned with the working place CMYK color profile as defined in Preferences > Color (which by default in Affinity apps is U.S. Web Coated v2, but which I have set on the video clip below to ISO Coated v2), and if your document CMYK color profile (where you place the PDF) is different (like on the video clip a new document is created with ISO Newspaper CMYK profile), there is a profile conflict and your interpreted K75 will get accordingly converted to four-color black! 

The way ligatures and OpenType features are interpreted is a kind of a typographic horror show so thanks for pointing it out! Now we know that if the source PDF has anything that really matters typographically, interpretation mode should never be used (it is really odd that the source document settings are completely ignored, yet you cannot affect the way ligatures and OpenType features get interpreted by using the settings of the hosting document, either).

But when using the Passthrough mode, you get the native K75 at PDF export no matter what your profile environment is (and no matter which kind of embedded profile, if any, the placed CMYK PDF uses). And you get the correct ligatures and OpenType features passed through, as well.

The video clip shows behavior in Designer 1.x but it is identical still in Designer 2.4.0 (Windows versions only tested):

 

 

[rzolau]

OK, it gets indeed complicated -- I must admit that I have not done very thorough documentation check, but is the behaviour you illustrated so well in your screencast documented anywhere? Now it makes me wonder what happens when the macOS Universal Control gets in the way.