I have a big problem. I have a flyer and it has 4+4 colors but I want to send it to the press in 1+1 cmyk (I mean C,M,Y = 0, K = variant).
So is it possible some way to do it with Photoshop?
Thanks for the help.
There is. Actually a few different ways of doing it. I would use Desaturate in PS, then examine each channel for the best grayscale representation. Select the channel you like the best and copy it. Then, delete all of the channels so they are all White ( still in CMYK mode ). Paste the channel you copied into the Black channel. Save it as a CMYK file. You could also do this by converting to Grayscale, Copy the Black channel, then converting again to CMYK and repeating the steps outlined above ( i.e., delete graphics in all channels and paste Black into the Black channel ).
Yeah, that works, but it generally looks like crap. That method tends to crush the blacks so much that you lose any semblance of shadow detail. A much better method, although using more steps is to convert the CMYK to RGB, use Channel Mixer or B&W to extract the best looking gray image, convert that to the Grayscale that corresponds to your output CMYK profile and paste that into the black channel of a new CMYK document.
Thanks the help guys, I just can't do one step, the last :facepalm:
How could I copy the grayscale image into the black channel? When I tried it, it pasted nothing... I copied the grayscale version to a blank new cmyk document, chosed the black channel and pasted it and it stayed blank (i mean transparent).
What did I wrong?
You should be able to Select All and then Copy the GS document. Then you have to target the black channel only of the CMYK document. Open the Channels Palette and click on the Black Channel. You should then be able to Paste into the Black Channel of the new document. You will want to make sure that the new CMYK document you make is the same pixel dimension as your GS document.