This document discusses the properties and uses of acrylic. It is a clear plastic material that resembles glass but is lighter, stronger, and more impact resistant than glass. There are two main types of acrylic: extruded and cell cast. Cell cast acrylic is of higher quality. Acrylic is commonly used in aquariums, swimming pools, water features, and architecture due to its clarity, strength, insulation properties, and ability to be shaped without seams. It has over 90% transparency and remains clear even when thick unlike glass which develops a green tint. Acrylic is also easier to work with than glass and has no size limitations.