Acrylic, or poly(methyl-methacrylate), is a transparent thermoplastic that has the transparency of glass at half the weight. Some of the key properties of Acrylic are optical clarity (clearer than polycarbonate), weather resistance, UV stability (does not yellow), impact resistance (many times greater than glass) and dimensional stability (does not shrink). There are three basic types of Acrylic: Cell Cast Acrylic, Continuous Cast Acrylic and Extruded Acrylic. Acrylic sheets can be shaped using a variety of tools. The most common tools used with acrylic sheets for cutting, engraving, marking, photo imaging, scoring / scribing, beveling, or drilling include Digital Laser Material Processing Technology (DLMPT), routers, saws and waterjets .