Tile and river rock commonly require a surface to moderate depth etch. When sandcarving river rock or tile, you have the option of a 5 mil self-stick photoresist film (additional adhesive can be applied to self-stick) for a surface etch, and the ability to etch deeper with 6 mil. The artwork image can determine the mil thickness; if it is detailed then a 5 mil is preferred.
—Liz Haas, Rayzist
Learn more about sandcarving natural stone.