Changing a color photo to print in black and one additional color only

Hi, Cathal,

Thanks. I guess I should have stated what I've tried so far, because it's similar to what you said.  I took the original image. I used "Select... Color Range ..." and selected a bunch of the red, with high fuzziness. I copied that selected-red and saved it onto a new image. Then I changed the mode to greyscale on the original image to dump out the color, changed it back to RGB color so I could add color again, and pasted the red-only-image back in.

Here's what I came up with (the before on top, the "two-color" version on bottom):
http://app25.com/pictures.html

It looks pretty good, but there may be lots of different reds in there, and the printer might say it's still a "four-color" image.

Did I explain things better this time?
--SD

So you are basically wanting to get rid of all shading of the colors so it is just one solid color - red and black and the whites/grays

I think so. So that using only black and all the greys, and some shade of red (to be determined) and all the different percentages of that shade of red, I get as close as I can to the original image, but the printer only needs two ink colors: black, and the one shade of red that I specify, based on my analysis of the photo.

So something like this

Here I have just set Tolerance to 100, no anti alias or continguous, fill method Color and paintbucket the red on the new layer