Polymethyl methacrylate PMMA also known as acrylic acrylic glass or plexiglass as well as by the trade names Crylux Plexiglas Acrylite Astariglas Lucite Perclax and Perspex among several others see below is a transparentthermoplastic often used in sheet form as a lightweight or shatterresistant alternative to glass The same material can be used as a casting resin or in inks and coatings among many other uses Although not a type of familiar silicabased glass the substance like many thermoplastics is often technically classified as a type of glass in that it is a noncrystalline vitreous substance hence its occasional historic designation as acrylic glass Chemically it is the synthetic polymer of methyl methacrylate The material was developed in 1928 in several different laboratories by many chemists