31 Jul 09 17:02
By turning CM off, the screen will not be showing a true representation of the colours in your file -- and therefore when you print them, whether via PDF of otherwise, you are likely to get the colours that are in your file, rather than the colours that you saw on the screen.
Isn't it the other way around? When you enable CM the screen shows you the colours as they will be printed, as opposed to how they are really selected? So by enabling CM while you draw you can pick the correct colours for printout instead of on-screen?
Of course, I really don't have a good grasp of how the whole colour management thing works which is why I try to avoid it... (my bad, I know.) I've gotten as far as calibrating my displays (using a Colorvision Spyder2) but in terms of extending the colour management to the printer I start to get frustrated. I do find that most printers now do a relatively decent job of mimicing the onscreen colours. They're off by a lot, but the general tone is usually at least correct (blues are blue not purple like they used to be). This is probably bad as it indicates some kind of automatic colour correction in the printer so if you really want to calibrate everything correctly you'd have to find a way to disable it. I suspect a lot of consumer printers (I'm looking at you, HP, with your horrible drivers) don't even let you do this.
I do find that the output with our usual printer (a Xerox Phaser) is pretty bad: reds turn to orange, but the drivers didn't come with any icc profile so I'm not sure how to fix it.
If you know of a particularly good tutorial on colour managing Coreldraw X4 I'd be happy to get a link... I'm currently using Windows 7 on most of my machines, which does seem to have a better system for colour management in general, if that helps at all.
But back to the immediate point, the illustrations in question will be figures for publication in a journal. The journal does all the typesetting and layout, so I'm hoping they will deal with any colour matching issues on their end to produce an output that sufficiently resembles the onscreen appearance. If not, I'll have to deal with those issues later, but in the meantime we're still working on the details of the paper and I needed to get drafts of the figures out to my co-authors, who don't use Coreldraw. All I wanted to do was be able to produce a PDF file which looked the same on my screen as the original CorelDraw file (with CM disabled). Yet, even on my screen the output PDF looked very different.
Finally, after fiddling with the settings I figure out how to do it. In the PDF Settings there's an Advanced tab, which has a section called Color Management. It defaults to "Output all objects as:" CMYK. I changed this to Native and it fixed the problem. Now at least onscreen the PDF looks the same.