[cairo] Spot colors (and CMYK)

[Jon Cruz]

On Jan 17, 2010, at 11:01 AM, Carl Worth wrote:

>> 
>> By "subtractive color" I actually mean just one very board thing -
>> "DeviceN". Think of it as one or more spot colors. In turn, a spot
>> color is just a name (as in "const char *name"), perhaps with
>> associated intensity value called "tint".
> 
> Perfect. Nice, clean definitions. And I think I'm following you up to
> this point.

This is very good to define. And I think it is a source of much pain.

I've seen a few broad interpretations of what DeviceN really is, and how it should be used. I've seen it used to cover just "CMYK plus extra spot colors", but then I've also seen it come out as "explicitly unmanaged color workflow, where even the same artist sending artwork to the print house for hardcopy *will* get different results on different days"

The former is ok, but the latter has the practical application problems that we want to avoid.

For some *very* pertinent information, Ralph Giles gave an excellent presentation today at an LCA miniconf on "New Ghostscript Colour Architecture"
http://libregraphicsday.org/proposal/57/new-ghostscript-colour-architecture