[scribus] No real CMYK black possible??

[Tino Schwarze]

On Sun, Jun 22, 2008 at 11:39:51PM +0200, Jan Schrewe wrote:

> > The file will go to an offset print shop[1]. They demand PDF/X3 with
> > ISOCoated v2 profile which is what I will provide. I fiddled around with gs
> > and cinepaint to check CMYK values and it doesn't look good at all (there's
> > no black any more in the files converted using tifficc in final PDF/X3
> > output), but I suppose this is some other glitch, maybe in gs (8.50) or in
> > cinepaint... which tool would allow me to check real CMYK values in PDF
> > output?
> 
> You don't need to convert your images from RGB to CMYK before you import them 
> into scribus. Scribus dows take care of that.

> The same goes for colors. As Andreas already said: Define a black in RGB and 
> let scribus take care of the conversion. You need to make sure that you use 
> the same input profiles for your colors and your images, though.

In theory, yes. But my tests show that RGB-0/0-0 black as a colored
rectangle is different from an RGB-0/0/0 black image. Even on screen it
looks very different! When I export to CMYK-PDF and look at it in
acroread8, it also looks _very_ different. It is not just some
almost-indistinguishable difference, you notice it instantly. And I'm
not going to try to print that.

I only use two profiles: sRGB for all RGB, ISOcoated v2 for all CMYK.
I only get a coherent appearance if I use a huge black image as
background as opposed to a color (either CMYK or RGB, I couldn't find
something that matched).

Something in Scribus' RGB image -> CMYK workflow is different from it's
RGB color -> CMYK workflow...

Tino.

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