Plaster is made from lime or gypsum, sand, and water and is one of the oldest building materials still in use—in fact, plaster applied to the Egyptian pyramids 4,000 years ago still holds its integrity.

Today, plaster is applied in three layers: a base coat, a thick coat of plaster for strength, and a finishing coat.

Plaster can be applied to many surfaces, including wood lath, metal mesh, wallboard, or masonry.

Some homes may even have ornamental plasterwork formed by hand or cast in molds and applied to walls and ceilings. Plaster can be applied in decorative patterns such as swirls and peaks.

Plaster can be painted or pigment can be mixed into it before it is applied. Such decorative treatments as wallpaper and tile can be easily applied over plaster.