Plaster
Plaster of Paris, or simply plaster, is a type of building material based on calcium sulphate hemihydrate. Plaster is similar to motar or cement. Like those materials plaster starts as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike motar and cement, plaster remains quite soft after drying, and can be easily manipulated with metal tools or even sandpaper.
