Which substrates are more ideal for deep sandcarving versus surface etching?

With both the dry- and wet-process photoresist stencil material, you can carve on flat and curved substrates. Brittle materials such as glass, crystal, stone, ceramic, marble, granite, and wood are perfect substrates for deep sandcarved designs. Metal, plastic, acrylic, and any other less brittle materials are ideal for surface etching rather than a deep carve.

   —IKONICS Imaging