Engraving materials:
wood, some plastics, paper, bamboo, horns, thin leather (wallet),
rubber stamp, photosensitive stamp, printing paper (mainly used for
engraving, less material to cut), sponge paper, etc. Burnt material.
Can't engrave materials: metal
(regardless of thickness), stone, ceramic, jewellery, jade, reflective
material, transparent glass, ivory, colorless transparent material, part
of white plastic (usually very smooth plastic is difficult to engrave)