Actually, the Norton one in this thread is the only one I’ve ever done. That other one you saw was done with galvanizing spray. I think that the laser reacts to the zinc in a different way from the paint. If you look at the first tile I did that way you will see that there are darker areas in the photo that actually engraved lighter than some of the mid tones. So I think it’s not as simple as more power yields darker result.
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