Grayscale text or CMYK in Publisher?

[Tim Be]

I set up a new document (for a paperback book) and chose grayscale/8 in the initial set-up box. But when I add a text frame, it is CMYK with values of 72-68-67-88. Is this correct, or should I change the text box’s setting to grayscale too?

And while I’m here, are those the best CMYK settings for type, or should it be 0-0-0-0?

Thanks.
 

Edited July 26, 2022 by Tim Be

[lacerto]

If your document color profile is Gray/8, colors are actually identical RGB values. To get pure black, you need to specify black as Gray 0, or alternatively R0 G0 B0. If you specify black as a CMYK value, it will be converted to equivalent Gray/RGB value (dark gray) according to currently active color profiles whenever you export to Grayscale or RGB. Conversely, if you specify R0 G0 B0 or Gray 0 and export using CMYK, you will get four-color black according to currently active color profiles.

So when working in Grayscale mode, it is best to define all colors (shades of gray) using Grayscale values. When you export, you may need to explicitly specify that the color space needs to be Grayscale (e.g., "PDF (for press)" has CMYK as the default color space). It is a good idea to also force color space conversion (to make sure any placed content will be properly converted to grayscale) and to NOT include the color profile. This way you will get device gray output with pure grayscale color values.

 

devicegrayblacks.pdf

[lacerto]

7 hours ago, Tim Be said:

But when I add a text frame, it is CMYK with values of 72-68-67-88. Is this correct, or should I change the text box’s setting to grayscale too?

Text frames have basically color values, too, but whatever you specify for the enclosed text will override the textframe default. What you see here are the CMYK values of Gray 0 (or RGB 0, 0, 0) shown in underlying CMYK color profile, which by default in Affinity apps is US Web Coated V2. When using this CMYK color profile, the equivalent of G0 is C72 M68 Y67 K88, If you use another CMYK color profile, the values would be different.

Notice the lock icon in the Color panel that by default is turned on. This means that whenever you switch the color model between e.g. RGB, Grayscale and CMYK, the color definition of currently selected objects will not actually change (be redefined), so the reason you saw the color values of a new textbox in CMYK was just that the CMYK was the current color model in the Color panel. If you turn the lock off, then switching the color model will actually redefine the color values of the selected objects immediately (when the lock is turned on, you need to use sliders or type in a color value in any of the boxes to actually redefine a color value).

[Tim Be]

Ok. So, the short story is, I don't need to do anything now while making the document - just leave it all as is - and be sure to check those export settings when that time comes. Is this right?

[lacerto]

5 hours ago, Tim Be said:

Ok. So, the short story is, I don't need to do anything now while making the document - just leave it all as is - and be sure to check those export settings when that time comes. Is this right?

Yes, as long as you have the objects that you want to be printed in pure black (like text) defined as G0 (using the grayscale color model), and export as shown, all is fine (so no CMYK values anywhere)! 

[thomaso]

On 7/28/2022 at 8:38 AM, lacerto said:

as long as you have (...) no CMYK values anywhere! 

Indeed a confusing workflow. While the button "K Only" in a CMYK document takes from an CMYK image its black channel only I would expect in a Grayscale document that using 0 0 0 100 would cause the same and result in 100 K if exported as grayscale. – Instead it appears that a CMYK black (100 K) in a Grayscale document exported as grayscale PDF can result in quite different values for 100K within 1 exported PDF.

For instance an export as PDF 1.7 + image colour conversion contains 85, 86, 90, 94 and 100% and gets the 100% only for RGB and Gray color definition but never for CMYK, even if it is the Affinity rich black / RGB equivalent.

Or another export, e.g. as PDF/X-4 (without image conversion) results in 4 different values for 100 K: 95, 98, 99 and 100%.

It feels quite strange that in particular CMYK causes those differences in a Grayscale .afpub while RGB (000) seems to be no question.