[pdftex] Two-color printing with pdftex

[Hartmut Henkel]

On Fri, 19 Nov 2010, André Bellaïche wrote:

> Is it possible to make two color PDF files with pdftex ? The goal to
> print with two plates only to reduce costs. The two colors may be
> black and one cmyk color, and should be able to be blended.

i guess so. You would need 2 pdftex runs and set a \ifplateone flag
differently for some plate #1 and plate #2. Inside the TeX input file
you would need to exercise discipline when working with colors, and to
use this \ifplateone switch for outputting of all that is allowed for a
plate or otherwise for outputting a white space there (reserved by e.
g., \kern, white \hrule or \vrule, or by switching text color to white).
Images you can pre-process (by convert etc.) that they are reduced to
the allowed colors before including them. Also here you can use the
switch to include from a set of two image files.

But it may be easier to let the printing house make their two plates by
some post-processing of a single PDF file, as Martin suggested. Anyway
it may be good to use only a limited number of colors in the 1st place.

Regards, Hartmut