Plaster, which consists of gypsum that has been cooked and powdered, has the property of quickly freezing when mixed with water. Calcium sulfate hemihydrate compound is the basic material of gypsum. Gypsum is obtained by grinding the compound of calcium sulfate dihydrate, called gypsum, and heating it up to 190 °C until most of the water in it is removed.

When gypsum, which is in powder form, is combined with water and turned into a paste, it hardens within a few minutes. 100 KG of plaster and 19 kg of water should be combined in the mixture. When too much water is used, pores are formed in the plaster, while if less water is used, the plaster becomes harder than it should be. Coarse or fine plaster can be created by adding substances that delay freezing to the plaster.

Plaster, also called plaster of Paris, was used for the coating of terracotta pots in the 18th century, as it was first used around Paris. Today, it is frequently used in various fields such as construction and medicine.

It can be applied outside or inside the building in constructions. Although the processes vary according to the material used, it is generally used in building decorations and to obtain smooth surfaces that can be painted.