Martin,
However after some testing. I totally agree that CMYK handling in R using pdf(..., colormodel = "cmyk") is not correct.
Looking at the source code of the function PostScriptSetCol in file src/librarygrDevices/src/devPS.c the conversion to CMYK looks correct. Looking at the generated pdf (qpdf: https://github.com/qpdf/qpdf is needed to uncompress the pdf) the numeric color values look correct, although the pdf contents don't exactly match those generated by PostScriptSetCol It is possible the problem is in the conversion that occurs when displaying/printing a pdf. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.