# My black text isn't black after exporting to PDF

Consider any standard plot, with true CMYK black text:

fakedata =
Transpose@{DatePlus[{2001, 1}, {#, "Month"}] & /@ Range[0, 99],
Accumulate[RandomVariate[NormalDistribution[0, 1], {100}]] - 2};
myplot = DateListPlot[fakedata, Joined -> True,
BaseStyle -> {20, CMYKColor[0, 0, 0, 1]}]


When I Export to PDF format, the text does not reproduce as true CMYK black, even if I specify its color as a CMYKColor. Rather, it comes out as CMYKColor[1,1,1,1], a mix of all four CMYK colors. This is a nuisance as my use case is to export these graphics for importing into an InDesign document, and the result is fuzzy-looking text. Strangely, the plot's Frame is not affected by this problem, which makes me think it is something to do with the text rendering algorithm.

Using ColorConvert doesn't help because that just rasterizes the image, which looks terrible. It is designed for images, not vector graphics.

 Export["test-converted3.pdf", ColorConvert[myplot, "CMYK"]] (* ugliness ensues *)


While I can fix the problem by getting the graphic designer to re-distill the PDF, I would much prefer to have a direct solution in Mathematica.

There is a supposedly obsolete option ColorOutput -> "CMYK", but it doesn't seem to make a difference.

I considered that the issue might be something to do with the way Mathematica antialiases text, but I couldn't work out what setting might affect that. Does anyone have any suggestions for a direct Mathematica solution?

• Is this a homework problem? Oct 25, 2013 at 4:44
• @MikeHoneychurch Haha - no, it's a do-it-in-my-lunchtimes-on-top-of-my-official-job problem :-D Oct 25, 2013 at 4:46
• An EPS file exported seems to preserve the CMYK value: 0 0 0 1 k. Don't know whether EPS->PDF conversion changes it though, and you may be using translucency... Oct 25, 2013 at 8:27
• @cormullion unfortunately EPS -> PDF is not an option because of font substitution issues. Oct 25, 2013 at 9:41
• @cormullion Exporting to EPS and converting generated EPS to PDF by Acrobat Distiller 11 I get all the text being Black(1.0) in DeviceGray color space according to the Preflight output and no CMYK colors at all in the PDF file. But yes, the EPS file contains 0 0 0 1 k operators - but I am not sure whether they correspond to the text or only to lines. Oct 25, 2013 at 10:38

Not a complete answer, but the PDF file exported from Mathematica 8.0.4 does not have CMYK text at all. All the text and GridLines are RGB and only Frame and FrameTicks are CMYK (but not frame tick labels). Here is output of Preflight in Acrobat 11.0.5: