I tried engraving leather (not 3D though). Yes, there was char. However, I sprayed the print with Fiebing’s Leather Sheen, and it set the engraved area and it doesn’t smear anymore.
This test print is only 1 by 1.5 inches. I can print it in a larger size (or a different image) and post it if you like. My guess is that the darker half of the image might be more detailed.
