Multichannel Help

DG
Posted By
david_grenier
Feb 26, 2004
Views
330
Replies
12
Status
Closed
I produce yellow page ads for local phone directories. I always get into trouble with photographs because I cannot figure out how to use the multichannels to get the desired image. Ive tried deleting the cyan and magenta channels, but the image needs to have no white, just 50 Yellow and shades of black. (the white needs to become the shades of the yellow color.) Can anyone provide me with instructions on how to do this?

thanks
david grenier

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Ed_Hannigan
Feb 26, 2004
Let me ask you this: are you printing on yellow paper? White always "prints" as the color of the paper, that is, it doesn’t print at all (unless you are using some kind of white ink process). Therefore, I would think all you have to do is make the photos grayscale.
DG
david_grenier
Feb 26, 2004
I have been using quark and using grayscale tiff files up until now (then coloring the box a 50% yellow in quark, but I have learned that their is a white box behind the image once I import it into Illustrator, making it impossible to trap. I was told that the only way around this is to use channels in photoshop.

The yellow pages print on white paper and it’s not a four color process for the yellows, it’s just Black and Yellow with the occasional red PMS color.
RW
Rene_Walling
Feb 26, 2004
I have been using quark and using grayscale tiff files up until now (then coloring the box a 50% yellow in quark, but I have learned that their is a white box behind the image once I import it into Illustrator

Just trying to clear things up. Are you working in Quark or Illustrator?

If working in Quark, a greyscale TIFF as you describe should be fine. If working in Illy, there is a way to colorize the background of the image, but I don’t know it offhand and Illy isn’t on the computer I am currently on…
JS
John_Slate
Feb 27, 2004
Some composite workflows from QXP will print the 50% yellow from colorizing the background with a reversed image of the grayscale, in which case you make a color swatch of 50Y/100K and colorize the photo with it. Separated workflows should be fine with just the background colorized.

In Illustrator you can just set a 50% yellow box behind the grayscale and set the grayscale to multiply. Presuming you have 9 or higher.

In Photoshop, copy the grayscale, and paste it into the black channel of a CMYK file. Then target the yellow channel in the channels palette, and fill with 50% tone. Leave the cyan and magenta channels in the file as they are— white.
DG
david_grenier
Feb 27, 2004
I would like to eliminate quark altogether and design straight in illustrator, but the yellow 50% issue has me going back and forth. My administrative program requires I produce the ads in illustrator…but I would first clean up the art in photoshop and import it…Without knowing how to colorize the grayscale image in photoshop or illustrator, i’m adding way to many steps and way too much time!!!

thanks
JS
John_Slate
Feb 27, 2004
To reiterate:

In Illustrator you can just set a 50% yellow box behind the grayscale and set the grayscale to multiply. Presuming you have 9 or higher.

In Photoshop, copy the grayscale, and paste it into the black channel of a CMYK file. Then target the yellow channel in the channels palette, and fill with 50% tone. Leave the cyan and magenta channels in the file as they are— white.
J
JasonSmith
Feb 27, 2004
"In Illustrator you can just set a 50% yellow box behind the grayscale and set the grayscale to multiply. Presuming you have 9 or higher."

Or in earlier versions set the greyscale to overprint – in the attributes palette.
JS
John_Slate
Feb 27, 2004
Or in earlier versions set the greyscale to overprint – in the attributes palette

That will not work in v8 with a placed grayscale tiff.

You can set the fill attribute to overprint, but the setting does not stick, or work.
DG
david_grenier
Feb 27, 2004
what happens if I have 9, but I need to downsave to 8? will it work then? I tried to Multiply the image as you suggested, then flatten it, but the layers do not flatten, and I get the Warning when I try and save that the image needs to be flattened.

david
JS
John_Slate
Feb 27, 2004
Flattening in Illustrator does not flatten layers, just transparency and raster effects.
DG
david_grenier
Feb 27, 2004
does it matter then if the image is saved as is? In photoshop you need to flatten your layers before saving for production…So, in Illustrator, will this method be useful for me? Will it print in only two colors?

Please understand, i have to be sure this will work, as I am about to begin a project that includes 675 ads…

me
JS
John_Slate
Feb 27, 2004
Test 1 ad in your workflow to see what happens.

I would think that an Illustrator 10 EPS file should work.

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