I am supposed to send some artwork to the printers tomorrow and their guidelines requires it to be CMYK.
I have installed the plugin Separate+ from the 'gimp-plugin-registy' package. I have also installed some ICC colour profiles from the 'icc-profiles' package.
When I try to use the Separate+ plugin all I can get it to output is an image that looks like the original but with the colours inverted.
How can I convert my image to CMYK?
Best Answer
I realize this is an old question, but I just stumbled upon it and found the answer. After you separate the image into the CMYK channels, you get a .tif image with 4 layers (one for each color). This image looks inverted because each area where this is white/grey represents a certain amount of cyan, magenta, yellow, or black.
Once you have this, just go to Image -> Separate -> Export and export your image as a .tif. This will repackage your image with the CMYK profile you choose, and when you view it, it will be the right print colors.
You can also use Image -> Separate -> Proof, and select the color profile of your monitor and it will generate a .tif preview with all the right colors. It's a pretty nice plugin!