Expert: LizaL - 11/22/2004

Question
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Followup To
Question -
when you create a duotone and then convert to cmyk, the color has a mixture created by RGB.
How can you create a duotone that is CMYK.  Specifically a problem when trying to produce a brown color.
thanks
Answer -
Hi Terry,

My big question is, are you using this duotone for print or Web purposes? I'm going to assume print, since you're needing the duotone in CMYK. There is a difference in overall appearance between screen and print resolution, as I'm sure you're aware.

Anyway, I walked through a quick duotone this morning to see if I could duplicate your problem, and it doesn't happen with me. I was able to take a color image, convert it to Grayscale, make a duotone, and convert it to CMYK just fine with no visible loss of color.

Can you post back and tell me the steps you use to create your duotone, and specifically, what you do to convert it to CMYK? All I did was go to the Image pulldown menu and change it from RGB to CMYK under the Mode selection, and it worked fine.

Can you also describe what your duotone looks like, or any other specific problems you're having with it? I didn't notice any loss of quality or color in mine when I converted.

Don't forget, if it's color quality and output you're concerned about, you can always click on the box with the diagonal line beside the duotone colors, and alter the duotone curve -- as you're creating your duotone. You use this curve just the way you use the regular Curves dialog box.

If you're still having trouble, please post back with the information I asked about, and we'll go from there!

Lisa
Hi Lisa,
Thank you so much for responding.
Here is what I am doing:
I convert the art to grayscale (under mode section)
then I make it a duotone (using forumula of pantone colors)
I then make it CMYK again (mode section)
When I do this there is a change in the color.  
Here are the colors I am using in my duotone: 4625 and 4645 (but I do the breakdown manually,so 0 cyan, 37M, 58Y and 28B (4645) and 0C, 60M, 100Y, and 79B (4625)
Then I convert to CMYK and the artwork has cyan in it.  
And yes this is for print.  I am using Photoshop CS.
Terry

Answer
Hi again Terry,

I see now what you're saying. I did a duotone with the specs you're using, and you're right, when you change it to CMYK, there is cyan in it.

I *think* the reason this is happening is because Photoshop's default black contains cyan -- and also magenta, and also yellow, as well as black. In other words, it's a rich black. So when you convert your image to grayscale, and you discard the color information, you're converting to Photoshop's version of a black and white image, which by default contains cyan.

But as for a workaround, I'm honestly not sure what to tell you. You could try, when you save the image, making sure not to check "embed color profile," which would make the image independent of any other means of color interpretation it might run into -- like when it goes to the printer's.

However, I'm not happy with that suggestion! This is something I'm going to do some research on, and if you can bear with me, I'll post back when I can get some more solid answers.

At any rate, that's what I think is happening. Maybe that will give you something to go on, in terms of finding out how to work around it. And I will post back if I find something!

Lisa