When using color conversion, without a PDF profile, the resulting PDF has become much bigger since version 13. Our example went from 127Kb to 7,9Mb. Our UCC profile is 8,6Mb. It seems like the ICC profile is included in the PDF. Something we, in version 12.5, only used to see when we defined a PDF profile. Is there a way we can use color conversion without 'including' the ICC profile in the PDF?

We may need to add a new option for this.

That would be great. As I don't have a clue about the impact of this feature request, is this feasible in a future 13.x version?

Saw that the issue was moved to the roadmap. Nice!

Today we have released a latest build with support for a "no-embed" flag on the prince-pdf-color-conversion property which you can use like this:

@prince-pdf {
    prince-pdf-color-conversion: url("target.icc") no-embed
}

The full syntax for the property is now:

prince-pdf-color-conversion: <url> [ rendering-intent || no-embed ]?
    
rendering-intent ::= absolute-colorimetric | ...

Is the same also possible for this scenario?

@prince-pdf {
    -prince-pdf-output-intent: url('Uncoated_Fogra47L_VIGC_300.icc');
    -prince-pdf-profile: 'PDF/A-1a';
}

So `no-embed` on the pdf-output-intent? At the moment I'm back at a the ±8Mb, instead of the ±100Kb I was at before when adding the 'PDF/A-1a' profile.

No, Prince always includes an OutputIntent when creating a PDF/A file, and the output intent includes an embedded ICC profile.

PDF/A requires all colours to be specified in a device-independent manner. Technically, if all colours in the document are device-independent then the OutputIntent could be omitted, but Prince cannot generate such files. However, if there are any (otherwise device-dependent) CMYK colours in the document then a CMYK ICC profile must be embedded in the PDF anyway, so omitting the OutputIntent would not reduce the file size much (if at all).