plaster of Paris


plaster of Paris
calcined gypsum in white, powdery form, used as a base for gypsum plasters, as an additive of lime plasters, and as a material for making fine and ornamental casts: characterized by its ability to set rapidly when mixed with water.
[1375-1425; late ME; so called because prepared from the gypsum of Paris, France]

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Quick-setting gypsum plaster consisting of a fine white powder, calcium sulfate hemihydrate, which hardens when moistened and allowed to dry.

It is made by heating gypsum to 250–360°F (120–180°C). Used since ancient times, plaster of paris is so called because of its preparation from the abundant gypsum found in Paris. It is used to make molds and casts for ceramics and sculptures, to precast and hold ornamental plasterwork on ceilings and cornices, and for orthopedic bandages (casts). In medieval and Renaissance times, gesso (plaster of paris mixed with glue) was applied to wood panels, plaster, stone, or canvas to provide the ground for tempera and oil painting.

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▪ building material
      quick-setting gypsum plaster consisting of a fine, white powder, calcium sulfate hemihydrate (see calcium), which hardens when moistened and allowed to dry. Plaster of paris is prepared by heating calcium sulfate dihydrate, or gypsum, to 120°–180° C (248°–356° F). With an additive to retard the set, it is called wall, or hard-wall, plaster.

      Used since ancient times, plaster of paris is so called because gypsum was early used near Paris to make plaster and cement. Plaster of paris is also used to precast and hold parts of ornamental plasterwork placed on ceilings and cornices and is used in medicine to make plaster casts to immobilize broken bones while they heal. Some modern sculptors work directly in plaster of paris. The speed at which the plaster sets gives the work a sense of immediacy and enables the sculptor to achieve the original idea quickly.

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Universalium. 2010.

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Look at other dictionaries:

  • Plaster of Paris — Plaster Plas ter, n. [AS., a plaster (in sense 1), fr. L. emplastrum, Gr. ?, ?, fr. ? to daub on, stuff in; ? in + ? to mold: cf. OF. plastre a plaster (in sense 2), F. pl[^a]tre. Cf. {Plastic}, {Emplaster}, {Piaster}.] [Formerly written also… …   The Collaborative International Dictionary of English

  • plaster of Paris — mid 15c.; originally it was made from the extensive gypsum deposits of Montmartre in Paris …   Etymology dictionary

  • plaster of Paris — n. [from use of gypsum from Montmartre in PARIS2 in its manufacture] a heavy white powder, calcined gypsum, which, when mixed with water, forms a thick paste that sets quickly: used for casts, moldings, statuary, etc …   English World dictionary

  • plaster of Paris — [[t]plɑ͟ːstər əv pæ̱rɪs, plæ̱s [/t]] N UNCOUNT Plaster of Paris is a type of plaster made from white powder and water which dries quickly. It is used to make plaster casts …   English dictionary

  • plaster of Paris — Most of the houses in France are made of plaster of Paris …   English expressions

  • plaster of Paris — plaster of Par|is [ˌpla:stər əv ˈpærıs US ˌplæs ] n [U] a mixture of a white powder and water that dries fairly quickly and is used for making plaster casts and to decorate buildings …   Dictionary of contemporary English

  • plaster of paris — plaster of par·is par əs n a white powdery slightly hydrated calcium sulfate CaSO4·1/2H2O or 2CaSO4·H2O that is made by calcining gypsum, forms a quick setting paste with water, and is used in medicine chiefly in casts and for surgical bandages * …   Medical dictionary

  • plaster of Paris — noun any of several gypsum cements; a white powder (a form of calcium sulphate) that forms a paste when mixed with water and hardens into a solid; used in making molds and sculptures and casts for broken limbs (Freq. 1) • Syn: ↑plaster •… …   Useful english dictionary

  • plaster of Paris — a preparation of gypsum (calcium sulphate) that sets hard when water is added. It is used in various modified forms in dentistry to make plaster model. It is also used in orthopaedics for preparing plaster cast …   Medical dictionary

  • plaster of Paris — a preparation of gypsum (calcium sulphate) that sets hard when water is added. It is used in various modified forms in dentistry to make plaster models. It is also used in orthopaedics for preparing plaster casts …   The new mediacal dictionary


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