[XeTeX] Overprinting (was Outputing PDFs in CMYK ColorSpace)

[Clinton Gormley]

> you 
> may want to consider learning ghostscript, which was specifically 
> designed to manipulate postscript and pdf files - however, ghostscript 

I've now got the CMYK conversion happening as well as it can happen
automatically, by using imagemagick to convert the embedded image to
CMYK, and using this command to convert a level 1 separated PS file back
to a PDF:

ps2pdf -dPDFSETTINGS=/printer -dCompatibilityLevel=1.3 -dUseCIEColor \
       -dColorImageResolution=200 -sProcessColorModel=DeviceCMYK \
        in.ps out.pdf

The one remaining bugbear is overprinting. I'm using the overprint
package from http://tex.aanhet.net/overprint/  (currently offline)

There is not much documentation available, so I'm not sure if I'm using
it correctly. It appears to be setting the first line/para to
\overprint, then reverting to \knockout.

I'm passing all paragraphs through the \para command, which in turn
calls the \text command. \text's #1 will never include \par's:

\newcommand{\text}[1]{\overprint#1\baselineskip=1.1em plus 1fill}%
\newcommand{\para}[1]{\par{\text{#1}\par}}%

Any ideas what I may be doing wrong?

thanks

Clint