Cast Acrylic for lithophanes
Both Plexiglass and Lexan are brand names. The key to a usable material is its resistance to heat. The bit turns at about 20,000 rpms. Plexiglass is not heat resistant and will melt or turn gummy. Lexan is a polycarbonate and is heat resistant. Cast acrylic is good. My favorite is Corian type material. You can also carve in products like Azec. (decking material)
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