I wanted to label the plants in my aquarium, so I tried marking on a small piece of slate I had on hand.
The text on that sign is 1.25" across and very sharp. I was worried the contrast would fade when the stone was wet, but not at all. Slate is my favorite thing now.
Settings posted by others got me into the right ballpark, I ended up on speed 900, power 30, 340 LPI.
Does anyone know where I can source flat slate chips, about .25" thick and roughly 2" x 2" ? Because I need a bucket of 'em now. So many ideas.