[XeTeX] spotcolor.sty and XeLaTeX

[William Adams]

On Nov 19, 2009, at 7:44 PM, Brian C. Ladd wrote:

> (1) All the specifics -- I will be honest, there are not that many  
> specifics:
>
> I have a document using black and tints of a single rgb color. I  
> worked in the rgb colorspace but I made sure that I only worked with  
> blends of white and/or black with my color.
> The publisher now says they want separations for the black and the  
> spot color. I matched my color, as best I could, with PMS colors as  
> PMS 1805 and started looking at my toolchain. I have PDF images  
> included into the the document (created with Inkscape) along with  
> some PNG graphics (created with the GIMP). The graphics are also  
> limited to the same tints used in the LaTeX.
>
> I am comfortable with producing PDF and then using a PDF specific  
> tool to produce the separations. The problem I have right now is  
> defining a spot color (so that the colors are defined as real tints  
> of the one spot color). The spotcolor package from CTAN is promising  
> but it is designed to work with pdflatex. Thus \pdfobj, \pdfobjref,  
> and \pdflastobj are giving me problems.
>
> I am using texlive 2008 (dowloading 2009 as I type). To be honest, I  
> am such a newb at understanding XeLaTeX that I didn't know what  
> graphics driver I should be specifying. I am also learning, slowly,  
> where in the tex directory tree, that all the goodies are supposed  
> to live.
>
> I am happy to admit that I don't even know what more specifics you  
> want to know. I am a competent programmer and I can find my way  
> around documentation and I am not afraid of LaTeX or PostScript. I  
> am trying to understand the special PDF objects being created in  
> spotcolor so that I can teach spotcolor.sty to play well with  
> XeLaTeX. I would then happily share it with the world to help others  
> who want to create a named color inside of a PDF document  
> constructed with XeLaTeX.
>
> If there are other specifics I can provide, I am happy to comply.


To be frank, the RGB bitmaps complicate things a bit. They will have  
to be re-processed somehow if you want to preserve them having both  
black and the colour in them which would probably need to be done by  
hand. How many bitmap images do you have?

The easiest thing (if the printer would be willing to accept it) would  
be to produce the document as CMYK, using only Magenta and black.  
You'd need to process all the graphics to make them CMYK only (w/ two  
empty plates, Cyan and Yellow) and then re-define all the colour calls  
in your document to appear only on the Magenta plate you've chosen.  
Then you'd tell the printer to suppress the Cyan and Yellow plates and  
to print Magenta as PMS 1805.

Or you could do this programmatically. Then you'd do the separations  
manually, producing two versions of the document:

1 - would be black and tints of grey
2 - would the spot colour as black and tints of grey

and have the printer composite the two in their RIP.

If memory serves, there is some sort of colour separation package on  
CTAN already.

If the printer won't accept that, then you'll have to engineer spot  
colour support yourself. First you'll need to open up all of your  
graphics and process them so that they are spot colour graphics ---  
you'll need PhotoShop and Illustrator for that. Then you'll have to  
write up the support in xelatex to insert the spot colour calls ---  
the spotcolor package should cover that.

An alternative would be to simply post-process the files using an  
easily created script in Enfocus PitStop (if the images can be placed  
entirely on the spot colour plate) --- if you'd like to send me a  
sample file, I'd be glad to look into doing this for you (professional  
courtesy, I'd be glad to do the entire job in my free time here at  
work). It might be, if I saw a sample file something else would come  
to mind --- please send me one off-list.

William

-- 
William Adams
senior graphic designer
Fry Communications
Sphinx of black quartz, judge my vow.