[NTG-context] Which color model shall I use

Jan U. Hasecke juh+ntg-context at mailbox.org
Mon Oct 1 09:23:26 CEST 2018


On 30.09.18 17:16, Henning Hraban Ramm wrote:

> 
> Hi juh,
> 
> you can define colors in several color models at once; CMYK makes most sense for professional printing.
> 
> e.g. \definecolor[CompanyBlue][r=0,g=0,b=1,c=1,m=1,y=0,k=0]
> 
> and see https://wiki.contextgarden.net/Command/setupcolors
> (I would activate rgb or cmyk colors via modes, if you produce different media)

I don't know how to enable this via modes.

> CMYK colors in SVG are difficult (I needed them in 2005, nowadays there’s a hardly supported standard for icc profile based colors).
> e.g. https://stackoverflow.com/questions/3405689/svg-image-with-cmyk-colours-is-it-possible
> https://www.w3.org/TR/SVGColor12/#icc-colors
> 
> Something about color profile handling in ConTeXt:
> https://wiki.contextgarden.net/PDFX
> 
> Now you must decide if you want to go the PDF/X-1a route (device dependent CYMK values) or PDF/X-3 (profiled colors).

How can I test, what colors are used in the resulting PDF? Currently I
pick the colors with a tool in Gimp to see what colors come up.

If I look at the colors this way the RGB values of the included svg are
always the original values defined by the file. All other values are not
the values I defined in the ConTeXt files.

I think this is due to the cmyk conversion of my screen.

\setupbackend[
 format=PDF/X-3,
 intent=ISO Coated v2 (ECI),
]

I tried with this for example.

Anyway. Wouldn't it be better to produce a RGB-PDF and let the ripper of
the print shop do the conversion? At least I can produce a RGB-PDF where
all colors are defined in the same manner.

juh


More information about the ntg-context mailing list