You're not going to get any depth out of engraving slate. Even at settings to cut through .25" acrylic it would only mark the surface for me.
If he any give you an extra piece I'd say experiment, starting at double the power you use to engrave plastic and proceed from there. You should get a lighter gray mark against the darker gray of the stone, but the contrast won't be terribly high.
The best success I has with slate was in a project outsourced to me (ie: I can't take credit for the idea, just had the equipment to do it for him). Engraving through a mask and using metallic silver paint surprisingly gives a very attractive finished look that is quite readable.
Sei |
