A funny thing happened when I was trying to see how cermark would act on a customer's tile. I sprayed ceramic cermark on the tile lightly (slightly see through) and burned it at the recommended settings. It made a green mark, very permanent.
I then used nothing and burned it at the same settings, 20 speed/50 power and got a white mark, also permanent.
Then I put the cermark on more thickly (not see through) and got a black mark.
This could be useful for making several tones on one tile, yes?
Any lines you see on the tile are from me - I started and stopped the job at the beginning because I didn't wait for it to warm up so one stripe got hit twice. The black mark was uneven from me not spraying, just brushing to test.
I'm not sure what kind of tile this is, he said it is "just ceramic tile", it says made in Italy on the back and is beige colored under the glaze.