Ghostscript: Convert CMYK Color to solid color with specific name

Question

is it possible to convert specific cmyk colors in pdf generation process?

In my case I have simulated colors for the customer like for example gold with value C15 M30 Y70 K20. This color must be replaced for the printer who uses a real gold foil. There for the CMYK value must be changed to C0 M100 Y0 K0 as well as the color must be a solid color instead of process color and last but not least it must get a specific color name. In this case „goldfoil“.

So can ghost script look for the specific CMYK values and replace them?

Any hint would be very helpful

Answer 1

No, you can't have Ghostscript alter colour values like that.

The correct way to do this is to create the PostScript program with a /Separation colour space, and define the alternate as a CMYK space with specific CMYK values to be used when the ink is not supported.

When the pritner supports the named ink 'goldfoil' it will print using the Gold ink (or foil in your case), when the named ink is not supported the printer will use the alternate space and colour values. That lets your customer see an approximation of the result on a CMYK printer, but your printer will be able to produce the true gold output.

Answer 2

I talked to the developer. The generated file is an svg that will be converted to PDF. I am not sure if this is here the right place but maybe you can give me some input. What I found out so far is that SVG is supporting ICC Profiles. So I thought to link an ICC profile and give the color the special name like so:

 <color-profile name=„ISOcoated_v2_eci" xlink:href="http://swatches.example.com/ISOcoated_v2_eci.icc"/>
     <circle fill=„#9C9475 icc-color(ISOcoated_v2_eci, Goldfolie"/>

Also the correct cmyk values are missing so can I combine it like so?

<color-profile name=„ISOcoated_v2_eci" xlink:href="http://swatches.example.com/ISOcoated_v2_eci.icc"/>
     <circle fill=„#9C9475 device-cmyk(0.00, 1.00, 0.00, 0.00) icc-color(ISOcoated_v2_eci, Goldfolie "/>

or so?

<color-profile name=„ISOcoated_v2_eci" xlink:href="http://swatches.example.com/ISOcoated_v2_eci.icc"/>
     <circle fill=„#9C9475 icc-color(ISOcoated_v2_eci,0.00, 1.00, 0.00, 0.00) icc-color(ISOcoated_v2_eci, Goldfolie "/>