Biscuit (pottery)

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A bisque porcelain bust Medaillon prince de Mayence Sevres.jpg
A bisque porcelain bust

Biscuit [1] [2] [3] [4] (also known as bisque) refers to any pottery that has been fired in a kiln without a ceramic glaze. This can be a final product such as biscuit porcelain or unglazed earthenware (such as terracotta) or, most commonly, an intermediate stage in a glazed final product.

Confusingly, "biscuit" may also be used as a term for pottery at a stage in its manufacture where it has not yet been fired or glazed, but has been dried so that it is no longer plastic (easily deformed). [5]

The porous nature of (fired) biscuit earthenware means that it readily absorbs water, while vitreous wares such as porcelain, bone china and most stoneware are non-porous even without glazing. [6] The temperature of biscuit firing is today usually at least 1000°C, although higher temperatures are common. [7] The firing of the ware that results in the biscuit article causes permanent chemical and physical changes to occur. These result in a much harder and more resilient article which can still be porous, and this can ease the application of glazes.

In situations where two firings are used, the first firing is called the biscuit firing, and the second firing is called the glost firing, or glaze firing if the glaze is fired at that stage.

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Ceramic Inorganic, nonmetallic solid prepared by the action of heat

A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick.

Kiln Oven that generates high temperatures

A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks. Various industries use rotary kilns for pyroprocessing—to calcinate ores, to calcinate limestone to lime for cement, and to transform many other materials.

Pottery Craft of making objects from clay

Pottery is the process and the products of forming vessels and other objects with clay and other ceramic materials, which are fired at high temperatures to give them a hard and durable form. Major types include earthenware, stoneware and porcelain. The place where such wares are made by a potter is also called a pottery. The definition of pottery, used by the ASTM International, is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products." In art history and archaeology, especially of ancient and prehistoric periods, "pottery" often means vessels only, and sculpted figurines of the same material are called "terracottas".

Porcelain Ceramic material

Porcelain is a ceramic material made by heating substances, generally including materials such as kaolinite, in a kiln to temperatures between 1,200 and 1,400 °C. The strength, and translucence of porcelain, relative to other types of pottery, arises mainly from vitrification and formation of the mineral mullite within the body at these high temperatures. Though definitions vary, porcelain can be divided into three main categories: hard-paste, soft-paste and bone china. The category that an object belongs to depends on the composition of the paste used to make the body of the porcelain object and the firing conditions.

Earthenware Nonvitreous pottery

Earthenware is glazed or unglazed nonvitreous pottery that has normally been fired below 1,200 °C (2,190 °F). Basic earthenware, often called terracotta, absorbs liquids such as water. However, earthenware can be made impervious to liquids by coating it with a ceramic glaze, which the great majority of modern domestic earthenware has. The main other important types of pottery are porcelain, bone china, and stoneware, all fired at high enough temperatures to vitrify.

Stoneware Term for pottery or other ceramics fired at a relatively high temperature

Stoneware is a rather broad term for pottery or other ceramics fired at a relatively high temperature. A modern technical definition is a vitreous or semi-vitreous ceramic made primarily from stoneware clay or non-refractory fire clay. Whether vitrified or not, it is nonporous ; it may or may not be glazed. Historically, around the world, it has been developed after earthenware and before porcelain, and has often been used for high-quality as well as utilitarian wares.

Creamware Cream-coloured, refined earthenware with a lead glaze over a pale body

Creamware is a cream-coloured refined earthenware with a lead glaze over a pale body, known in France as faïence fine, in the Netherlands as Engels porselein, and in Italy as terraglia inglese. It was created about 1750 by the potters of Staffordshire, England, who refined the materials and techniques of salt-glazed earthenware towards a finer, thinner, whiter body with a brilliant glassy lead glaze, which proved so ideal for domestic ware that it supplanted white salt-glaze wares by about 1780. It was popular until the 1840s.

Hard-paste porcelain

Hard-paste porcelain, sometimes "true porcelain", is a ceramic material that was originally made from a compound of the feldspathic rock petuntse and kaolin fired at very high temperature, usually around 1400 °C. It was first made in China around the 7th or 8th century, and has remained the most common type of Chinese porcelain.

Biscuit porcelain Unglazed white porcelain

Biscuit porcelain, bisque porcelain or bisque is unglazed, white porcelain treated as a final product, with a matte appearance and texture to the touch. It has been widely used in European pottery, mainly for sculptural and decorative objects that are not tableware and so do not need a glaze for protection.

Underglaze

Underglaze is a method of decorating pottery in which painted decoration is applied to the surface before it is covered with a transparent ceramic glaze and fired in a kiln. Because the glaze subsequently covers it, such decoration is completely durable, and it also allows the production of pottery with a surface that has a uniform sheen. Underglaze decoration uses pigments derived from oxides which fuse with the glaze when the piece is fired in a kiln. It is also a cheaper method, as only a single firing is needed, whereas overglaze decoration requires a second firing at a lower temperature.

Chinese ceramics Pottery and porcelain from China

Chinese ceramics show a continuous development since pre-dynastic times and are one of the most significant forms of Chinese art and ceramics globally. The first pottery was made during the Palaeolithic era. Chinese ceramics range from construction materials such as bricks and tiles, to hand-built pottery vessels fired in bonfires or kilns, to the sophisticated Chinese porcelain wares made for the imperial court and for export. Porcelain was a Chinese invention and is so identified with China that it is still called "china" in everyday English usage.

Mintons English pottery company (1793–2005)

Mintons was a major company in Staffordshire pottery, "Europe's leading ceramic factory during the Victorian era", an independent business from 1793 to 1968. It was a leader in ceramic design, working in a number of different ceramic bodies, decorative techniques, and "a glorious pot-pourri of styles - Rococo shapes with Oriental motifs, Classical shapes with Medieval designs and Art Nouveau borders were among the many wonderful concoctions". As well as pottery vessels and sculptures, the firm was a leading manufacturer of tiles and other architectural ceramics, producing work for both the Houses of Parliament and United States Capitol.

Ceramic glaze Fused coating on ceramic objects

Ceramic glaze is an impervious layer or coating of a vitreous substance which has been fused to a pottery body through firing. Glaze can serve to color, decorate or waterproof an item. Glazing renders earthenware vessels suitable for holding liquids, sealing the inherent porosity of unglazed biscuit earthenware. It also gives a tougher surface. Glaze is also used on stoneware and porcelain. In addition to their functionality, glazes can form a variety of surface finishes, including degrees of glossy or matte finish and color. Glazes may also enhance the underlying design or texture either unmodified or inscribed, carved or painted.

Glaze defects Flaws in a ceramic glaze

Glaze defects are any flaws in the surface quality of a ceramic glaze, its physical structure or its interaction with the body.

This is a list of pottery and ceramic terms.

Gzhel

Gzhel is a Russian style of blue and white ceramics which takes its name from the village of Gzhel and surrounding area, where it has been produced since 1802.

China painting Art of painting on ceramics

China painting, or porcelain painting, is the decoration of glazed porcelain objects such as plates, bowls, vases or statues. The body of the object may be hard-paste porcelain, developed in China in the 7th or 8th century, or soft-paste porcelain, developed in 18th-century Europe. The broader term ceramic painting includes painted decoration on lead-glazed earthenware such as creamware or tin-glazed pottery such as maiolica or faience.

Lead-glazed earthenware Earthenware with a lead-based ceramic glaze

Lead-glazed earthenware is one of the traditional types of earthenware with a ceramic glaze, which coats the ceramic biscuit body and renders it impervious to liquids, as terracotta itself is not. Plain lead glaze is shiny and transparent after firing. Coloured lead glazes are shiny and either translucent or opaque after firing. Three other traditional techniques are tin-glazed, which coats the ware with an opaque white glaze suited for overglaze brush-painted colored enamel designs; salt glaze pottery, also often stoneware; and the feldspathic glazes of Asian porcelain. Modern materials technology has invented new vitreous glazes that do not fall into these traditional categories.

A potbank is a colloquial name for a pottery factory in North Staffordshire used to make bone china, earthenware and sanitaryware.

Ceramic art Decorative objects made from clay and other raw materials by the process of pottery

Ceramic art is art made from ceramic materials, including clay. It may take forms including artistic pottery, including tableware, tiles, figurines and other sculpture. As one of the plastic arts, ceramic art is one of the visual arts. While some ceramics are considered fine art, such as pottery or sculpture, most are considered to be decorative, industrial or applied art objects. Ceramics may also be considered artefacts in archaeology. Ceramic art can be made by one person or by a group of people. In a pottery or ceramic factory, a group of people design, manufacture and decorate the art ware. Products from a pottery are sometimes referred to as "art pottery". In a one-person pottery studio, ceramists or potters produce studio pottery.

References

  1. Kara, Alpagut (2004). "An Investigation Into Bloating Behaviour Of Bone China Body During Biscuit Firing". Key Engineering Materials . 264–268: 1717–1722. doi:10.4028/www.scientific.net/KEM.264-268.1717. S2CID   135947610.
  2. Kara, Alpagut; Stevens, Ron (2003). "Interactions Between A Leadless Glaze And A Biscuit Fired Bone China Body During Glost FiringPart III: Effect Of Glassy Matrix Phase". J. Eur. Ceram. Soc. 23 (10): 1617–1628. doi:10.1016/S0955-2219(02)00403-X.
  3. Plešingerová, Beatrice; Klapáč, Miroslav; Kovalčíková, Miriam (2002). "Moisture Expansion Of Porous Biscuit Bodies Reason Of Glaze Cracking" (PDF). Ceramics-Silikáty . 46 (4): 159–165.
  4. Dale, Alfred J.; German, William L. (1964). Modern Ceramic Practice. Maclaren & Sons.
  5. Osborne, Harold (ed), The Oxford Companion to the Decorative Arts, p. 78, 1975, OUP, ISBN   0198661134
  6. Dodd, Arthur E.; Murfin, David (1994). Dictionary Of Ceramics (3rd ed.). Institute Of Minerals. ISBN   9780901716569.
  7. Ryan, William; Radford, C. (1987). Whitewares Production, Testing, and Quality Control: Including Materials, Body Formulations, and Manufacturing Processes. International Series on Systems and Control. Pergamon Press on behalf of the Institute of Ceramics (Great Britain). ISBN   9780080349275.