[pdftex] Two-color printing with pdftex

[Taco Hoekwater]

On 11/20/2010 04:02 PM, Jeffrey McArthur wrote:
> The way I did color separation in the past was moderately complicated. I
> used some font tricks with virtual fonts.
>
> I used tfmtopl to create the .PL file for each font.
> Then I hacked the .PL file into a VPL file.
> If I wanted the text for that font/color combination to print, then it set
> the char, otherwise it just did a move.
>
> Then you switch the virutal fonts to print in one color or the other.
>
> Rules are managed the same way by setting the rule in the VPL file and not
> in TeX.
>
> Graphics are done by using a special command in the VPL file.
>
> This is very ugly, but it worked.

I think this is pretty good way of doing it (I used a similar approach
a few years ago), but it can get rather complex in documents with lots
of fonts.

These days, I usually create a composite pdf that uses only the C and
K parts of CMYK, and I expect the printer to be able to handle that
(either by splitting the pdf into the two composites in preprocessing,
or by telling the device driver of the press that C is the secondary
color and that MY can be ignored). If the printer claims he cannot do
that, I search the yellow pages for a better printing house.

Best wishes,
Taco