Better known by its short name PMMA or the terms acrylic glass, polyacrylic or the trade name Plexiglas. Polymethyl methacrylate is an amorphous plastic which in its pure form is perfectly clear; its translucence for visible light is better than that of mineral glass. For this reason, it is wide used for optical components such as lenses and spectacle glasses as well as glazing. In many of these applications, PMMA is a competitor of polycarbonate. While it is much less expensive, it does not exhibit polycarbonate’s excellent mechanical properties and has above all a poorer impact strength. PMMA is polar and not resistant to organic solvents. PMMA can be coated very well in the plasma, for example with scratch-resistant DLC coats or anti-reflective coats. In the early 1930s, PMMA was the first transparent plastic material which could be thermoformed; it was used to make curved covers, panes and hoods. To this day, PMMA is primarily known by the brand name Plexiglas registered by Otto Röhm back in 1933.