On Sep 16, 2010, at 6:52 AM, Jonatã Bolzan wrote:
Get my point: I set in Inkscape the fill of a shape with C0 M50 Y100 K0 that is orange. I need in the C off-set platewith no cyan ink, M off-set plate with 50% of magenta ink, Y off-set plate with 100% of yellow ink and K off-set plate with no black ink. If I save it in a PDF in RGB, I'll need a ICC profile to convert these values to CMYK. But doing this will never give me the real values I want (C0 M50 Y100 K0). They will always convert the colors based on the profile conversion. What can I do? That is what I want to say, the ICC profile is not a must to have an output in CMYK because some people (like me) just want the exact values used in the draw.
Yes.
*If* you work in an SVG document with a CMYK profile specified, then you get those four discrete CMYK values stored. Then if you bring it into Scribus you will end up with a PDF that preserves exactly the percentages you had specified.
The CMYK profile is a must, since you can't just say "Magenta ink". What you can say is "The Magenta ink as mixed in north america for web-based coated printing". Then when the print shop gets it they say "oh, he wants Magenta 50% in SWOP, but todays calibration for offset press number two on the third floor needs to be told 48% to get the desired end color" and they do their magic behind their doors to make things match any references and proofs you have.
So far all the normal cases I have encountered in real life where an artist or designer *thought* he wanted to control exact CMYK ink application in the plates, the desire turned out to be misguided. That was the *how* of the designer trying to end up with consistent color. The *why* is not to control ink levels, but to end up with the same color specified and the same color he had been getting last week or last month. With a CMYK profile involved the latter is easily achievable; without any specifics on the CMYK specified, it is not.
Even in the case where a print shop does no color management at all, things are much better if you come in saying "Here are my CMYK values as defined in SWOP". They then have a standard to be held to and it is *their* responsibility to get print output on their specific presses that is close enough to SWOP 50% magenta. Even in cheap one-off shops in China our users have seen good color prints with just that simple mechanism (essentially saying "here is what it should end up looking like, match it")