CMYK file for prepress

[JamesX521]

I have PSD file that is going for prepress. The tonality/background is mostly black.

1. My RGB will be converted to CMYK. Any tips to retain the vivid colors. Whatever "Out of gamut" meant.... All I remember is that it had something to do with fixing RGB to CMYK color... right?

2. Do I need to worry about the black printing properly or are the press operators aware of CMYK black color issues?

Thanks.

[urstwile]

You're going to lose some vividness when you go to CMYK. That's just a given, CMYK inks do not do well with certain colors, in particular oranges and greens.

Check with your printer and ask them for their advice on the best route for your CMYK conversion.

[Drazan]

Out of gamut.

Gamut is the range of colors for a specific application.

CMYK colors typically have a far less range of colors than RGB. THis is why many rgb to cmyk conversions end up dull.

If you open up a copy of your image in photoshop and use the >>mode>>cmyk to convert it, then you will get a color shift in your rbg document. Sometimes this is hardly noticable and other times it completely throws your color out of wack.

The other thing about digital press is that many do not like black shades that range above 60% as they will loose detail fast after that.

Here's a link on color gamut
http://www.cdman.com/graphics/color/gamut.html

and here's a link to help with photoshop rgb to cmyk conversion when there is colorshift.
http://www.designer-info.com/Writing/rgb_to_cmyk.htm

typically whenever possible it is best to work in CMYK. There's also a little warning sign when you chose a color on screen that is outside printable gamut. Click the warning sign and it choses it's nearest neighbor and you can adjust from there.

Good Luck
Jade