Start with the gray image by itself in a grayscale document. Select all and cut to the clipboard. Convert the grayscale to CMYK — the same as your final document. Select the black channel the paste. Now you have a CMYK file with info only the black channel which you can drag onto the final image.
I’m confused as to how that would work. When I select the black channel after converting the greyscale image back to CMYK, there’s hardly any information in it. It makes the whole sky look like it’s white. I need some information in the entire photo (unless it was completely white to begin with) for this to work for me.
If I got your steps wrong let me know.
1. Convert orig. photo to greyscale. Save as tif.
2. Convert tif back to cmyk.
3. Deselect all channels except black.
4. Copy/paste the black channel into CMYK document.
Jennifer
Carl,
I thought again about your post. Here’s what I did. Tell me if it’s right.
1. Converted orig. photo to a greyscale. Save as tif.
2. Convert tif back to cmyk.
3. Select all and copy.
4. Go into channels. Deselect all channels but the black.
5. Select the black channel and paste the image that I copied in #3 into the black channel.
6. Now I have a "full" representation of the photo but it’s only on the black channel.
Did I get it right this time?
Thanks! Jennifer
Only work on the layer you wish to be black-only. Put that image into its own grayscale document.
1. Select all
2. Cut to clipboard, which gives you a blank document.
3. Convert to CMYK with the same profile as the final CMYK document.
4. Select the black channel.
5. Paste.
6. Select the composite channel.
7. Drag the image to the final CMYK document.
You’ll end up with a layer that is black-only.
Nope. That didn’t work either. It created a new layer with cmyk channels.
Still confused. Sorry.
Jennifer
Be sure your destination document has the same CMYK profile.
You are awesome! Sometimes I need hand-holding. Thanks. That worked like a charm. I am working in all the same profile so it should be good to go.
I find now that I have to use a higher opacity to see the entire grayscale in the background (from 10% to 30-40%) but that should be okay. Now I have a real black image to work with.
Thanks so much! The forum people are a great resource.
Jennifer
May I ask, given that the document is 4-color, why it’s advantageous or desirable to have that bottommost layer on the K plate only? I’m not challenging the practice, just wanting to understand it.
The biggest reason for me is to avoid color shifting out of neutral on press. I know in a perfect world that’s not supposed to happen, but well… 😉 It’s better to avoid problems than to deal with them.
There’s also the K.I.S.S. philosophy. If I can accomplish a desired output with fewer components, in this case inks, then I will.
Also, Jennifer mentioned that the gray will be ghosted, so there’s no need for a rich black to help with the dynamic range.
All makes sense, Carl, avoiding the cursed color shift in particular. Thanks.
Yes, I just wanted a true black, not the muted color produced with the "rich black" image in the background. Also, I didn’t want the chance for the color shift, especiall at 10% to blur the image. My printer is good, but why give him a headache on 12 pages? This is for a calendar and the image is a black ghost behind the days of the month. The full color version of the same photo is on the previous (facing) page.
Thanks again to Carl for getting me through this problem. It’s great to have an addition to the arsenal. That gives me more ideas, too.
Jennifer
Carl,
Hope you are still looking at this post. I made all the photos grayscale and pasted them in the black channel as you stated above. It worked in each individual document. Then came time to drag each grayscale-in-black-channel-only CMYK tif into a layer in my full color document. Presto-change-o, they are now CMYK again! I tried to cut from the black channel in the referenced tif and pasting into the black channel of the CMYK document, but when I do *nothing* shows up.
What did I do wrong? Boy, do I feel like a dummy now…
Jennifer
Why are you making an intermediate document?
just paste the grayscale images into the black channel of the final doc.
I have 13 documents. 12 photos and then the comp PSD with all the layers of Month names, weekday names, etc.
I take each full color photo that I want to be the backer of the month layers, make it grayscale, do all the stuff Carl suggested and turn it into a CMYK tif with all the info in the black channel. Then he said to drag that into the comp CMYK document and all the info for that layer would be in the black channel.
But I must be doing it wrong because it is converted once again into a CMYK "gray" layer, with info on each layer, if I drag the new CMYK-with-info-on-the-black-channel-only onto the comp doc.
It won’t let me paste or drag into the black channel only of the PSD comp document. *Nothing* shows up when I try to do that. I have the marching ants for my selection on the PSD, but there’s nothing in it.
*Nothing* shows up when I try to do that.
Are you sure you have the proper layer selected?
Presto-change-o, they are now CMYK again!
Jennifer, I’m not sure what else to say. If you drag one CMYK file on another with the same profile, there’s nothing to covert. It will only convert if there’s a profile mismatch. Try dragging the color image to the gray and see what happens.
I closed the document last night and went home frustrated. I couldn’t get the drag and drop to show up or it went in all channels. This morning it works. It could be that they weren’t??? the same profile, even though I haven’t changed my profile in a week..until last night when I changed it to another, then changed back this morning before I opened the document.
I don’t know what it was…perhaps the profile mismatch??? but it worked this morning.
Thanks for your patience.
Jennifer
and this is the reason why the industry is a mess…
no one listens to prepress people…
Huh? Is that a slam? I was listening intently…I just don’t always *get* it the first time.
Thanks to all who helped.
J
Jennifer,
It is not an insult. It is a fact that your issues are a common problem at the developmental stage of the software – combined by the fact that people who have a strong say in the application are primarily photographers, and not print production professionals.
You are not the only one with said frustrations.
HEAR HEAR!
Prepress joke…
Q: How do you spot a designer with a photography background? A: 16 bit rgb 1200 dpi, untagged….average image file size 120 Meg. (with rasterised text, 1 bonus point)
(400% total ink, 1 bonus point)
I have a CMYK document and I want one of the layers to be a greyscale image with black only. The rest of the layers are full color with different opacities to show through to the bottom greyscale image. I realize that when I place a greyscale image in a full color document, it becomes CMYK. How do I make sure that layer is only black? I am scaling the opacity back to 10% on that layer anyway.
The image is for a calendar page. The background image is a photo at 10% opacity. The next layers up are the actual day squares at 90% opacity in white, and then the month and year are in a color. I really want the background to be 10% black.
I thought I would use the channel mixer but I’m not sure how that works. I’m a long time user, but this is new territory for me. Any help would be great!
If I understand you correctly, I think you can use this option: Select layers and:
Image->Adjustments->Channel mixer-> and choos "monochrome" Tray to adjust channel.
Pawel 🙂
