PMMA – Polymethylmethacrylate
An acrylic resin based on methyl methacrylate. It has become generally known under the trade name Plexiglas®. On the one hand, PMMA is approx. 60 times more elastic than window glass but on the other hand it is approx. 10 times more permeable than silicate glass. Of course, the hardness of its surface does not correspond to that of glass but compared with other materials it can be easily polished to high brilliance. As to weight, Polymethylmethacrylate is much more lightweight than normal window glass.