[Gimp-user] Question about GIMP CMYK support.

[John R. Culleton]

On Tuesday 07 August 2007, Chris Mohler wrote:
> On 8/7/07, Bhavin Suthar <bhavin.suthar at gmail.com> wrote:
> > Can someone tell me the truth behind this? Does this also mean
> > that if you write text on image (like your jpeg Canon photos)
> > then they can't be printed properly?
>
> Point #1 is almost accurate.  The true part: GIMP does not natively
> support CMYK yet.  It will in time, and there is a plug-in if you
> truly need CMYK separations.  The false part: you can't use GIMP to
> prepare for printing.  You certainly can, but be aware of the
> RGB->CMYK translation process - eg, there is no way to print the
> color #0000FF in CMYK.
>
> Point #2 is pretty much FUD.  I occasionally convert something to
> CMYK in PS just to check the shift, but if you are a "graphics
> professional" [sic] you should already be aware of the RGB colors
> that exist outside of CMYK color space and avoid them.  A cheap
> inkjet printer will show you the result of converting your RGB to
> CMYK if you really need to know - and this type of proof (a "hard"
> proof) is more accurate anyway, owing to the fact that all monitors
> operate on the principal of additive light (hence RGB), and most
> printers operate on subtractive light (thus CMYK).  A "soft" proof
> can easily[1] be obtained by using imagemagick[2].
>
> Short answer: I doubt you need CMYK.  You certainly won't be
> prevented from printing your photos by not using it.  Many desktop
> printers expect RGB input these days[3].
>
> Chris

I would expect that flesh tones would give the most trouble in 
converting from RGB to CMYK . Among free software programs Krita, 
TeX, Cinepaint  and Scribus handle CMYK natively, and all but TeX can 
use ICC color profiles.  Gimp and Inkscape don't yet, and that limits 
their acceptablity in the publishing world despite their other 
excellent features.  Book designers want CMYK plus ICC profiles and 
won't consider a product that lacks that capability for color work. 

The free programs listed above that most closely approximate Gimp are 
Cinepaint (a Gimp offshoot0, and Krita.  But neither has the range of 
other features offered by Gimp.  and Krita only runs under the KDE 
desktop found on many Linux systems.

It is possible to conceive of a workflow that involved doing most of 
the creative work in Gimp but a final checkout/conversion to CMYK in 
e.g., Krita or Scribus. 

Color separations where needed for the press can be prepared by 
specialized prepress software and need not involve the publisher. 
Most printers will accept color files in pdf form so long as the 
color is in CMYK model.  It helps if the PDF adheres to the X3 
specification however.  Since Scribus already has all this a Gimp to 
Scribus workflow makes some sense. 
-- 
John Culleton
Able Indexing and Typesetting
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