[DVIPDFMx] Overprinting with xelatex

[Clinton Gormley]

> If you're just adding a flat background colour you can simulate
> overprinting by adding the background colour to the type:

yeah - that's the problem. It's likely that there will be pictures as
backgrounds.

> To post-process it, I'd either use PitStop, or just make a process
> plan in our RIP --- perhaps Ghostscript could do something similar.
> 

> There should be a special which can be added to the .pdf to set
> overprinting for a block of type, but I've always been able to avoid
> the need to look that up.

The special, according to the PDF specs, looks pretty simple. I'm just
not sure how to use a special in xelatex

> 
> William
>