R plots pdf() does not allow spotcolors?

Even so, this would depend on what your publisher/printer
requires in what you submit. It would be important to obtain
from them a full and exact specification of what they require
for colour printing in files submitted to them for printing.

No one else has mentioned this, but the publisher is trying to make
money, not make your life easier.  Sometimes the right thing to do is
say "Hey - you guys are the experts at this, you convert my RGB pdfs
to the correct format".  It's worthwhile to push back a bit to
publishers and get them to do their job.

Hadley

Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/