A matrix is formed into a desired shape by pouring transparent liquid material into a mold. The material progressed from the liquid to the gelatinous state. Laser sculpting steps are performed when the material is still in a gelatinous condition to form small spots in the matrix. Because the material...http://www.google.com.au/patents/US6537479?utm_source=gb-gplus-sharePatent US6537479 - Subsurface engraving of three-dimensional sculpture
