Plaster Facts for Kids

Elaborate stucco (plaster) reliefs decorating the Chateau de Fontainebleau were hugely influential in Northern Mannerism. There is a plaster low-relief decorative frieze above.

Modern tools for plastering

Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. Another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces.

The most common types of plaster mainly contain either gypsum, lime, or cement, but all work in a similar way. The plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then hardens.

Plaster can be relatively easily worked with metal tools or even sandpaper, and can be moulded, either on site or to make pre-formed sections in advance, which are put in place with adhesive. Plaster is not a strong material; it is suitable for finishing, rather than load-bearing, and when thickly applied for decoration may require a hidden supporting framework, usually in metal.

Forms of plaster have several other uses. In medicine plaster orthopedic casts are still often used for supporting set broken bones. In dentistry plaster is used to make dental impressions. Various types of models and moulds are made with plaster. In art, lime plaster is the traditional matrix for fresco painting; the pigments are applied to a thin wet top layer of plaster and fuse with it so that the painting is actually in coloured plaster. In the ancient world, as well as the sort of ornamental designs in plaster relief that are still used, plaster was also widely used to create large figurative reliefs for walls, though few of these have survived.

Images for kids

Clay plaster base coat on split oak lath held in place with straw and manure, covered with a lime plaster top coat, Old Economy Village, Pennsylvania (1827)
Lime setting-coat on clay plaster with straw binder. Applied to hand-split lath over a timber framed wall of a brick family house at Old Economy Village, Pennsylvania
An orthopedic cast for the hand made out of plaster.
Example of a stenciled plaster design
Himeji Castle, Himeji, Hyogo Prefecture, Japan
Early 19th Century plasterer at work - painting by John Cranch (1751–1821)
19th century stucco plasterwork from House of Borujerdies in Kashan, Iran
Face plaster casting bandage application
Plasterwork in Pompeii (79 AD)
Figure of a woman; 5th century; painted plaster; height: 38.4 cm (15"), width: 14.7 cm (6"), depth: 9.6 cm (4"); Metropolitan Museum of Art
Seated Voltaire; by Jean-Antoine Houdon; 1778; plaster, tinted to imitate terracotta; overall: 35.6 x 14.6 x 20 cm (14" x 5¾" x 8"); Metropolitan Museum of Art
Young girl; first modeled: 1779–1780; plaster; height: 36.8 cm (14½"); Metropolitan Museum of Art
Nymph; 1805–1810; plaster; height: 155.6 cm (5'1¼"); Metropolitan Museum of Art
Photo of a plaster model of an ornamental oeil-de-boeuf for the new Louvre; circa 1856; Metropolitan Museum of Art
The Young Mother; by Bessie Potter Vonnoh; circa 1896; plaster; Portland Museum of Art (Portland, US)

Plaster facts for kids

Images for kids

See also