Full procedure can be found at: mrsec.wisc.edu Two chess rooks are created using 3D printing. Light supplied by a computer projector creates free radicals which induce polymerization of 1,6-hexanediol diacrylate. After each layer is polymerized, the elevator is slightly lowered and the process is repeated. A dye is included to prevent light from penentrating much below the surface of the solution.

Source: YouTube