[scribus] No real CMYK black possible??

[Jan Schrewe]

Tino Schwarze schrieb am Montag, 23. Juni 2008:
> 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.

Are you using the same profile for "Solid Colors" and "RGB Images" in the 
color management settings? Scribus can apply different profiles to them. Does 
the image have a profile embedded? Is the rendering intent the same as for 
the colors?

That is something I have had quite some problems with.