This is a first and second attempt at printing a halftone photo onto cheap (Home Depot, 11 cents) ceramic tile.
I created the halftone using Pixelmator on the Mac. For the second, I converted to black and white, and then adjusted the levels to brighten up the light areas while leaving the darkest areas dark.
I used full speed, full power, 340 dpi.
Red, green, and black Sharpies (on the second one).
Wiped away with a magic eraser (and saliva).