I have photograph of a singer with a black background (taken in the dark against a spotlight) that has all sorts of subtle colors and fuzzy edges. My client wants to put on a black shirt. I set up a simulated process version, but they didn't want to pay for that many colors. So now we're back to printing CMYK on black with a white or discharge underbase. Someone suggested to me that we just print the CMY and omit the black screen - punching the black halftones out of the other colors, letting the black shirt act as the black. I faked the seps up in Photoshop to see how it looks, and something definitely looks...wrong about it. But I can't put my finger on what it is.

Has anyone ever tried this and what were your results like?