Expert: Glen Demers - 9/24/2009

Question
Hi,
Is it possible to change the channel colours from cmyk or rgb to any other (spot) colours?
I want to make originals for textile screen printing and think the result would be better if I mixed other colours then cmyk or rgb (these are not photographic images, but illustrations that consist of more then just monochrome surfaces).
In other words: is there a way to make photoshop calculate what would be the most accurate way to construct the image from four spot colours "far" from each other in the colour circle.
I have tried making selections from the different channels and filled new spot-channels and then deleting the cmyk-channels, but with this method a lot of tweaking the spot channels with curves etc. is needed to make the result acceptable.
"Quad tone" does not work since you must change the image to grayscale first.

I think there should be a way to do this, but i can't figure out how...

Regards,
Emanuel"

Answer
Hi Emanuel,

Go to Image>Mode>Multichannel. This will switch you into multi channel mode, you can go to the channels palette and see the composite channel is gone.
Double clicking on the channel in the channel palette will bring up a dialog box that let's you re-name the channel. Clicking on the colored swatch next to Color will bring up the color picker and that lets you change the color of the channel.
As you work on a single channel, it is in grayscale but if you view multiple channels they are displayed with the channels colors.

Hope this helps,
Glen Demers
Adobe Certified Expert, Photoshop 7
Prepress Technician, Best Printing Online
www.bestprintingonline.com

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