Grayscale image to CMYK image

[Jalan]

Sometimes when working with CMYK images and Grayscale images, I need to combine them. I have a grayscale image I want to copy and paste into the CMYK layout. No matter how I try, I cannot make come over just on the black plate. It always wants to go rich black, sort of like converting an RGB black to CMYK.
I've turned off profiles, I've changed profiles, I've stared at the screen until my eyeballs fell out... nothing is working.

I used to think I knew a lot about this program... I'm starting to think differently. :twisted:
I need to go back to ColorIt

[DCurry]

Target the Black channel and then paste.

[Jalan]

That's the bizarre thing, I do. When I try to paste it on the black plate, it just draws a marquis/marching ants. of the selenction but nothing is inside it.

[Sparky]

I just launched Photoshop CS created a new document in CMYK, drew a few designs and made sure I had the entire color spectrum covered. I then opened a known CMYK file and copied a part of it into a new document, then converted it to grayscale and copied that. I then went to the CMYK file and selected "Channels" and made sure the black channel was the only one selected, then pasted my grayscale image into it. when I clicked on the cmyk button to see all channels, there was my grayscale image in black only on top of all the CMYK crap I had drawn.

So this tells me you may have not done something correctly :? :roll:

[DCurry]

Originally Posted by Jalan1974

That's the bizarre thing, I do. When I try to paste it on the black plate, it just draws a marquis/marching ants. of the selenction but nothing is inside it.

Probably a layer issue. Try this - make a new layer and fill with white. Now target the black channnel and paste.

[Jalan]

Sorry, I must not have stated everything clear.
The idea of me wanting to copy and paste a grayscale into the CMYK image is because they laid out the whole brochure in photoshop. I needed to insert some logos so I can't exactly fill in the whole thing white or else it's a major pain to remove that white or else have the rest of the layout dissappear. Upon a new layer, I select the black channel and paste. The marching ants come and no image. I select all channels and paste, then the image appears but is a rich black build. I end up changing it through curves and that works.
This also happens with copying bitmaps into the CMYK layout.

[DCurry]

Convert the grayscale to CMYK using Maximum Black Generation, which will force most or all of the black to the K channel, then drag into your other CMYK document.

[dimitri]

easy, once you paste your greyscale into a cmyk image and it apears on all plates, go into your channel mixer (image -> adjustment -> channel mixer) and and get rid of all other channels there. go to the black plate and put a bit from the cyan plate in.
You can also just click the "monochrome" tick box.

that is by the way also the best way to convert cmyk files into greyscale, as you have full controll over which colour you want to use. Cyan does not always have to be the best colour for a greyscale.

cheers Dimitri