porcelain

(pôr'sə-lĭn, pōr'-, pôrs'lĭn, pōrs'-)

1. A hard, white, translucent ceramic made by firing a pure clay and then glazing it with variously colored fusible materials; china.
2. An object made of this substance.

[French porcelaine, cowry shell, porcelain, from Old French, from Old Italian porcellana, from feminine of porcellano, of a young sow (from the shell's resemblance to a pig's back), from porcella, young sow, diminutive of porca, sow, from Latin, feminine of porcus, pig.]

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Background

The term porcelain refers to a wide range of ceramic products that have been baked at high temperatures to achieve vitreous, or glassy, qualities such as translucence and low porosity. Among the most familiar porcelain goods are table and decorative china, chemical ware, dental crowns, and electrical insulators. Usually white or off-white, porcelain comes in both glazed and unglazed varieties, with bisque, fired at a high temperature, representing the most popular unglazed variety.

Although porcelain is frequently used as a synonym for china, the two are not identical. They resemble one another in that both are vitreous wares of extremely low porosity, and both can be glazed or unglazed. However, china, also known as soft-paste or tender porcelain, is softer: it can be cut with a file, while porcelain cannot. This difference is due to the higher temperatures at which true porcelain is fired, 2,650 degrees Fahrenheit (1,454 degrees Celsius) compared to 2,200 degrees Fahrenheit (1,204 degrees Celsius) for china. Due to its greater hardness, porcelain has some medical and industrial applications which china, limited to domestic and artistic use, does not. Moreover, whereas porcelain is always translucent, china is opaque.

Hard-paste or "true" porcelain originated in China during the T'ang dynasty (618-907 A.D.); however, high quality porcelain comparable to modern wares did not develop until the Yuan dynasty (1279-1368 A.D.). Early Chinese porcelain consisted of kaolin (china clay) and pegmatite, a coarse type of granite. Porcelain was unknown to European potters prior to the importation of Chinese wares during the Middle Ages. Europeans tried to duplicate Chinese porcelain, but, unable to analyze its chemical composition, they could imitate only its appearance. After mixing glass with tin oxide to render it opaque, European craftspeople tried combining clay and ground glass. These alternatives became known as soft-paste, glassy, or artificial porcelains. However, because they were softer than genuine porcelain, as well as expensive to produce, efforts to develop true porcelain continued. In 1707 two Germans named Ehrenfried Walter von Tschimhaus and Johann Friedrich Bottger succeeded by combining clay with ground feldspar instead of the ground glass previously used.

Later in the eighteenth century the English further improved upon the recipe for porcelain when they invented bone china by adding ash from cattle bones to clay, feldspar, and quartz. Although bone china is fired at lower temperatures than true porcelain, the bone ash enables it to become translucent nonetheless. Because it is also easier to make, harder to chip, and stronger than hard porcelain, bone china has become the most popular type of porcelain in the United States and Britain (European consumers continue to favor hard porcelain).

Raw Materials

The primary components of porcelain are clays, feldspar or flint, and silica, all characterized by small particle size. To create different types of porcelain, craftspeople combine these raw materials in varying proportions until they obtain the desired green (unfired) and fired properties.

Although the composition of clay varies depending upon where it is extracted and how it is treated, all clays vitrify (develop glassy qualities), only at extremely high temperatures unless they are mixed with materials whose vitrification threshold is lower. Unlike glass, however, clay is refractory, meaning that it holds its shape when it is heated. In effect, porcelain combines glass's low porosity with clay's ability to retain its shape when heated, making it both easy to form and ideal for domestic use. The principal clays used to make porcelain are china clay and ball clay, which consist mostly of kaolinate, a hydrous aluminum silicate.

Feldspar, a mineral comprising mostly aluminum silicate, and flint, a type of hard quartz, function as fluxes in the porcelain body or mixture. Fluxes reduce the temperature at which liquid glass forms during firing to between 1,835 and 2,375 degrees Fahrenheit (1,000 and 1,300 degrees Celsius). This liquid phase binds the grains of the body together.

Silica is a compound of oxygen and silicon, the two most abundant elements in the earth's crust. Its resemblance to glass is visible in quartz (its crystalline form), opal (its amorphous form), and sand (its impure form). Silica is the most common filler used to facilitate forming and firing of the body, as well as to improve the properties of the finished product. Porcelain may also contain alumina, a compound of aluminum and oxygen, or low-alkali containing bodies, such as steatite, better known as soapstone.

The Manufacturing
Process

After the raw materials are selected and the desired amounts weighed, they go through a series of preparation steps. First, they are crushed and purified. Next, they are mixed together before being subjected to one of four forming processes—soft plastic forming, stiff plastic forming, pressing, or casting; the choice depends upon the type of ware being produced. After the porcelain has been formed, it is subjected to a final purification process, bisque-firing, before being glazed. Glaze is a layer of decorative glass applied to and fired onto a ceramic body. The final manufacturing phase is firing, a heating step that takes place in a type of oven called a kiln.

Crushing the raw materials

• First, the raw material particles are reduced to the desired size, which involves using a variety of equipment during several crushing and grinding steps. Primary crushing is done in jaw crushers which use swinging metal jaws. Secondary crushing reduces particles to 0.1 inch (.25 centimeter) or less in diameter by using mullers (steel-tired wheels) or hammer mills, rapidly moving steel hammers. For fine grinding, craftspeople use ball mills that consist of large rotating cylinders partially filled with steel or ceramic grinding media of spherical shape.

Cleaning and mixing

• The ingredients are passed through a series of screens to remove any under- or over-sized materials. Screens, usually operated in a sloped position, are vibrated mechanically or electromechanically to improve flow. If the body is to be formed wet, the ingredients are then combined with water to produce the desired consistency. Magnetic filtration is then used to remove iron from the slurries, as these watery mixtures of insoluble material are called. Because iron occurs so pervasively in most clays and will impart an undesirable reddish hue to the body if it oxidizes, removing it prior to firing is essential. If the body is to be formed dry, shell mixers, ribbon mixers, or intensive mixers are typically used.

Forming the body

• Next, the body of the porcelain is formed. This can be done using one of four methods, depending on the type of ware being produced:
  • soft plastic forming, where the clay is shaped by manual molding, wheel throwing, jiggering, or ram pressing. In wheel throwing, a potter places the desired amount of body on a wheel and shapes it while the wheel turns. In jiggering, the clay is put on a horizontal plaster mold of the desired shape; that mold shapes one side of the clay, while a heated die is brought down from above to shape the other side. In ram pressing, the clay is put between two plaster molds, which shape it while forcing the water out. The mold is then separated by applying vacuum to the upper half of the mold and pressure to the lower half of the mold. Pressure is then applied to the upper half to free the formed body.
  • stiff plastic forming, which is used to shape less plastic bodies. The body is forced through a steel die to produce a column of uniform girth. This is either cut into the desired length or used as a blank for other forming operations.
  • pressing, which is used to compact and shape dry bodies in a rigid die or flexible mold. There are several types of pressing, based on the direction of pressure. Uniaxial pressing describes the process of applying pressure from only one direction, whereas isostatic pressing entails applying pressure equally from all sides.
  • slip casting, in which a slurry is poured into a porous mold. The liquid is filtered out through the mold, leaving a layer of solid porcelain body. Water continues to drain out of the cast layer, until the layer becomes rigid and can be removed from the mold. If the excess fluid is not drained from the mold and the entire material is allowed to solidify, the process is known as solid casting.

Bisque-firing

• After being formed, the porcelain parts are generally bisque-fired, which entails heating them at a relatively low temperature to vaporize volatile contaminants and minimize shrinkage during firing.

Glazing

• After the raw materials for the glaze have been ground they are mixed with water. Like the body slurry, the glaze slurry is screened and passed through magnetic filters to remove contaminants. It is then applied to the ware by means of painting, pouring, dipping, or spraying. Different types of glazes can be produced by varying the proportions of the constituent ingredients, such as alumina, silica, and calcia. For example, increasing the alumina and decreasing the silica produces a matte glaze.

Firing

• Firing is a further heating step that can be done in one of two types of oven, or kiln. A periodic kiln consists of a single, refractory-lined, sealed chamber with burner ports and flues (or electric heating elements). It can fire only one batch of ware at a time, but it is more flexible since the firing cycle can be adjusted for each product. A tunnel kiln is a refractory chamber several hundred feet or more in length. It maintains certain temperature zones continuously, with the ware being pushed from one zone to another. Typically, the ware will enter a preheating zone and move through a central firing zone before leaving the kiln via a cooling zone. This type of kiln is usually more economical and energy efficient than a periodic kiln.
• During the firing process, a variety of reactions take place. First, carbon-based impurities burn out, chemical water evolves (at 215 to 395 degrees Fahrenheit or 100 to 200 degrees Celsius), and carbonates and sulfates begin to decompose (at 755 to 1,295 degrees Fahrenheit or 400 to 700 degrees Celsius). Gases are produced that must escape from the ware. On further heating, some of the minerals break down into other phases, and the fluxes present (feldspar and flint) react with the decomposing minerals to form liquid glasses (at 1,295 to 2,015 degrees Fahrenheit or 700 to 1,100 degrees Celsius). These glass phases are necessary for shrinking and bonding the grains. After the desired density is achieved (greater than 2,195 degrees Fahrenheit or 1,200 degrees Celsius), the ware is cooled, which causes the liquid glass to solidify, thereby forming a strong bond between the remaining crystalline grains. After cooling, the porcelain is complete.

Quality Control

The character of the raw materials is important in maintaining quality during the manufacturing process. The chemical composition, mineral phase, particle size distribution, and colloidal surface area affect the fired and unfired properties of the porcelain. With unfired body, the properties evaluated include viscosity, plasticity, shrinkage, and strength. With fired porcelain, strength, porosity, color, and thermal expansion are measured. Many of these properties are monitored and controlled during manufacturing using statistical methods. Both the raw materials and the process parameters (milling time and forming pressure, for example) can be adjusted to achieve desired quality.

The Future

High-quality porcelain art and dinnerware will continue to enhance the culture. Improvements in manufacturing will continue to increase both productivity and energy efficiency. For instance, a German kiln manufacturer has developed a prefabricated tunnel kiln for fast firing high-quality porcelain in less than 5 hours. Firing is achieved by partly reducing atmosphere at a maximum firing temperature of 2,555 degrees Fahrenheit (1,400 degrees Celsius). The kiln uses high-velocity burners and an automatic control system, producing 23,000 pounds (11,500 kilograms) of porcelain in 24 hours.

Manufacturers of porcelain products may also have to increase their recycling efforts, due to the increase in environmental regulations. Though unfired scrap is easily recycled, fired scrap poses a problem: mechanically strong and therefore hard to break down, it is usually dumped into landfills. However, preliminary research has shown that fired scrap can be reused after thermal quenching (where the scrap is reheated and then quickly cooled), which makes it weaker and easier to break down. The scrap can then be used as a raw material.

Porcelain appears to be playing a more important role in technical applications. Recent patents have been issued to Japanese and American companies in the area of electrical insulators and dental prostheses. NGK Insulators, Ltd., a Japanese manufacturer, has developed high-strength porcelain for electrical insulators, whereas Murata Manufacturing Co. has developed low-temperature-sintering porcelain components for electronic applications.

Where To Learn More

Books

Campbell, James E. The Art and Architecture Information Guide Series, vol. 7:Pottery and Ceramics, A Guide to Infonnation Sources. Gale Research, 1978.

Camusso, Lorenzo, ed. Ceramics of the World: From Four Thousand B.C. to the Present. Harry N. Abrams, 1992.

Charles, Bernard H. Pottery and Porcelain. Hippocrene Books, 1974.

Jones, J. T. and M. F. Bernard. Ceramics, Industrial Processing and Testing. Iowa State University Press, 1972.

Periodicals

Shashidhar, N. and J. S. Reed. "Recycling Fired Porcelain." Ceramic Bulletin. Vol. 69, No. 5, 1990, pp. 834-841.

Wilson, Lana. "Charcoal and Metallic Salts." Ceramics Monthly. October, 1987, p. 36.

[Article by: L. S. Millberg]

A high-grade ceramic ware characterized by high strength, a white color (under the glaze), very low absorption, good translucency, and a hard glaze. Equivalent terms are European porcelain, hard porcelain, true porcelain, and hard paste porcelain. See also Glazing; Pottery.

Porcelain is distinguished from other fine ceramic ware, such as china, by the fact that the firing of the unglazed ware (the bisque firing) is done at a lower temperature (1800–2200°F or 1000–1200°C) than the final or glost firing, which may be as high as 2700°F (1500°C). In other words, the ware reaches its final state of maturity at the maturing temperatures of the glaze.

The white color is obtained by using very pure white-firing kaolin or china clay and other pure materials, the low absorption results from the high firing temperature, and the translucency results from the glass phase. See also Ceramics.

A glazed or unglazed vitreous ceramic whiteware used for electrical, chemical, mechanical, structural, or thermal components.

Benjamin Franklin viewed the domestic manufacture of porcelain as an important step toward economic independence from England, and it ultimately became intimately linked with the industrialization of the nation. However, its production in the United States was never as crucial as stoneware and redware production.

Porcelain, first made in China during the Tang dynasty (618–907 A.D.), remained a Chinese secret sought by the West for many hundreds of years. It was not until 1708 and 1709, after the German ceramist Johann Friedrich Böttger had discovered its secret, kaolin, that true hard-paste porcelain was produced outside of China. In 1738, Andrew Duché of Savannah, Georgia, made the first recorded piece of porcelain in North America, "a small teacup … very near transparent."

Around 1825 some twenty skilled craftsmen from England and France were employed to make porcelain for the Jersey Porcelain and Earthenware Company in Jersey City, New Jersey. Other ventures followed in Philadelphia. In 1853, when the Crystal Palace Exhibition of the Industry of All Nations was held in New York City, work by the Haviland Brothers, who had a china shop there, was much praised. By the mid-1860s, Parian ware, a type of porcelain having the appearance of marble, became so popular that no fashionable Victorian parlor would be without a piece or two. Ott and Brewer of Trenton, New Jersey, sold a wide line of Parian ware. From the 1880s on, Belleek, a light, marvelously thin, ivory-colored porcelain variant of Parian, named after its Irish town of origin, became the greatest American ceramics success story.

After the influential Centennial Exhibition in Philadelphia, art pottery became a serious business in America. Porcelain, while a minor branch of the industry, had its champions in M. Louise McLaughlin (1847–1939) and especially Adelaide Alsop Robineau (1865–1929). By the 1930s, porcelain found wide application in industry and began to be studied at colleges, universities, and art schools such as Cranbrook. An intense interest in porcelain continues.

Bibliography

American Ceramics: The Collection of Everson Museum of Art. New York: Rizzoli, 1989.

Frelinghuysen, Alice Cooney. American Porcelain, 1770–1920. New York: The Metropolitan Museum of Art, 1989.

LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!

A material formed by the fusion of feldspar, silica, and other minor ingredients. Most dental porcelains are glasses and are used in the manufacture of artificial teeth, facings, jackets, and occasionally denture bases and inlays.

• Glass and Ceramics - porcelain: hard, fine-grained, nonporous ceramicware, usu. translucent and white
• Ceramics and Glassmaking - porcelain: hard, white, nonporous ceramic ware composed of kaolin, feldspar, and quartz

"Fine China" redirects here. For the band, see Fine China (band).

This article is about the ceramic material. For other uses, see Porcelain (disambiguation).

Chinese moon flask, 1723-35, Qing Dynasty

Ming Dynasty porcelain at the Brooklyn Museum in New York City

Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between 1,200 °C (2,192 °F) and 1,400 °C (2,552 °F). The toughness, strength, and translucence of porcelain arise mainly from the formation of glass and the mineral mullite within the fired body at these high temperatures.

Porcelain derives its present name from old Italian porcellana (cowrie shell) because of its resemblance to the translucent surface of the shell.^[1] Porcelain can informally be referred to as "china" in some English-speaking countries, as China was the birthplace of porcelain making.^[2] Properties associated with porcelain include low permeability and elasticity; considerable strength, hardness, toughness, whiteness, translucency, and resonance; and a high resistance to chemical attack and thermal shock.

For the purposes of trade, the Combined Nomenclature of the European Communities defines porcelain as being "completely vitrified, hard, impermeable (even before glazing), white or artificially coloured, translucent (except when of considerable thickness) and resonant." However, the term porcelain lacks a universal definition and has "been applied in a very unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common" (Burton 1906).

Contents 1 Scope, materials and methods 1.1 Scope 1.2 Materials 1.3 Methods 2 History 2.1 Chinese porcelain 2.2 European porcelain 2.2.1 Meissen 2.2.2 Soft paste porcelain 2.2.3 Other developments 3 Types of porcelain 3.1 Hard paste 3.2 Soft paste 3.3 Bone 4 Other uses 4.1 Electric insulating material 4.2 Building material 5 Manufacturers 6 See also 7 References 8 Further reading 9 External links

Scope, materials and methods

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Soft-paste porcelain Swan tureen, 1752-6, Chelsea.

Flower centrepiece, 18th century, Spain.

Scope

The most common uses of porcelain are for utilitarian wares and artistic objects. It can be difficult to distinguish between stoneware and porcelain because this depends upon how the terms are defined. A useful working definition of porcelain might include a broad range of ceramic wares, including some that could be classified as a stoneware. Porcelain is used to make household wares, decorative items and objects of fine art amongst other things.

Materials

Further information: Pottery

Kaolin clay is the primary material from which porcelain is made, even though clay minerals might account for only a small proportion of the whole. The word "paste" is an old term for both the unfired and fired material. A more common terminology these days for the unfired material is "body", for example, when buying materials a potter might order an amount of porcelain body from a vendor.

The composition of porcelain is highly variable, but the clay mineral kaolinite is often a raw material. Other raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse and alabaster.

For more details on these formulations, see soft-paste porcelain and hard-paste porcelain.

The clays used are often described as being long or short, depending on their plasticity. Long clays are cohesive (sticky) and have high plasticity; short clays are less cohesive and have lower plasticity. In soil mechanics, plasticity is determined by measuring the increase in content of water required to change a clay from a solid state bordering on the plastic, to a plastic state bordering on the liquid, though the term is also used less formally to describe the facility with which a clay may be worked. Clays used for porcelain are generally of lower plasticity and are shorter than many other pottery clays. They wet very quickly, meaning that small changes in the content of water can produce large changes in workability. Thus, the range of water content within which these clays can be worked is very narrow and the loss or gain of water during storage and throwing or forming must be carefully controlled to keep the clay from becoming too wet or too dry to manipulate.

Methods

The following section provides background information on the methods used to form, decorate, finish, glaze, and fire ceramic wares.

Forming: It is described in the articles Pottery and Ceramic forming techniques.

Glazing: Unlike their lower-fired counterparts, porcelain wares do not need glazing to render them impermeable to liquids and for the most part are glazed for decorative purposes and to make them resistant to dirt and staining. Great detail is given in the glaze article. Many types of glaze, such as the iron-containing glaze used on the celadon wares of Longquan, were designed specifically for their striking effects on porcelain.

Decoration: Porcelain wares may be decorated under the glaze using pigments that include cobalt and copper or over the glaze using coloured enamels. Like many earlier wares, modern porcelains are often biscuit-fired at around 1,000 degrees Celsius, coated with glaze and then sent for a second glaze-firing at a temperature of about 1,300 degrees Celsius or greater. Another early method is once-fired where the glaze is applied to the unfired body and the two fired together in a single operation.

Firing: In this process, green (unfired) ceramic wares are heated to high temperatures in a kiln to permanently set their shapes. Porcelain is fired at a higher temperature than earthenware so that the body can vitrify and become non-porous.

History

Chinese porcelain

Song Dynasty celadon porcelain with a fenghuang spout, 10th century, China.

Main article: Chinese ceramics

See also: List of Chinese inventions

Porcelain originated in China. Traditionally, there have been two styles of Chinese porcelain: red and blue, or otherwise referred to as blue-and-white wares. Red porcelain was much more difficult to fire than blue, and tended turn a faded grey colour if the firing was improperly controlled^[3]

Although proto-porcelain wares exist dating from the Shang Dynasty (1600–1046 BCE), by the Eastern Han Dynasty period (196–220) high firing^{[clarification needed]} glazed ceramic wares had developed into porcelain.^[4][5] Porcelain manufactured during the Tang Dynasty (618–906) was exported to the Islamic world, where it was highly prized.^[5][6] Early porcelain of this type includes the tri-colour glazed porcelain, or sancai wares. The exact dividing line between proto-porcelain and porcelain wares is not a clear one to date. Porcelain items in the sense that we know them today could be found in the Tang Dynasty,^[7] and archaeological finds has pushed the dates back to as early as the Han Dynasty (206 BCE – 220 CE).^[4][8] By the Sui Dynasty (581–618) and Tang Dynasty (618–907), porcelain had become widely produced.

Eventually, porcelain and the expertise required to create it began to spread into other areas of East Asia. During the Song Dynasty (960–1279), artistry and production had reached new heights. The manufacture of porcelain became higly organised and the kiln sites, those excavated from this period, could fire as many as 25,000 wares.^[8] By the Ming Dynasty (1368–1644), porcelain art was being exported to Europe. Some of the most well-known Chinese porcelain art styles arrived in Europe during this era, such as the coveted blue-and-white wares.^[9] The Ming Dynasty controlled much of the porcelain trade, which were further expanded to all over Asia, Africa and Europe through the Silk Road. Later, Portuguese merchants began direct trade over the sea route with the Ming Dynasty in 1517 and were followed by Dutch merchants in 1598.^[6]

Korean and Japanese porcelain also have long histories and distinct artistic traditions.^{[citation needed]}

European porcelain

Fonthill vase is the earliest Chinese porcelain object to have reached Europe. It was a Chinese gift for Louis the Great of Hungary in 1338.

Section of a letter from Francois Xavier d'Entrecolles about Chinese porcelain manufacturing techniques, 1712, re-published by Jean-Baptiste Du Halde in 1735.

These exported Chinese porcelains were held in such great esteem in Europe that in the English language china became a commonly–used synonym for the Franco-Italian term porcelain. Apart from copying Chinese porcelain in faience (tin glazed earthenware), the soft-paste Medici porcelain in 16th-century Florence was the first real European attempt to reproduce it, with little success.

Early 16th century, the Portuguese brought back samples of kaolin clay, which they discovered in China to be essential in the production of porcelain wares, but the Chinese techniques and composition to manufacture porcelain was not yet fully understood.^[8] Countless experiments to produce porcelain had unpredictable results and would meet with failure.^[8] In the German state of Saxony, the search concluded with an eventual discovery in 1708 by Ehrenfried Walther von Tschirnhaus that produced a hard, white, translucent type of porcelain specimen with a combination of ingredients, including kaolin clay and alabaster, mined from a Saxon mine in Colditz.^[10][11] It was closely guarded as a trade secret by the Saxon enterprise.^[11][12]

In 1712, many of the elaborate Chinese manufacturing secrets for porcelain were revealed throughout Europe by the French Jesuit father Francois Xavier d'Entrecolles and soon published in the Lettres édifiantes et curieuses de Chine par des missionnaires jésuites. The secrets of porcelain manufacturing, which d'Entrecolles read about and witnessed in China, were now known and began being used in Europe.^{[13][14][15][16][17]}

Meissen

Von Tschirnhaus and Böttger were employed by Augustus the Strong and worked at Dresden and Meissen in the German state of Saxony. Tschirnhaus had a wide knowledge of European science and had been involved in the European quest to perfect porcelain manufacture when in 1705 Böttger was appointed to assist him in this task. Böttger had originally been trained as a pharmacist; after he turned to alchemical research, it was his claim that he knew the secret of transmuting dross into gold that attracted the attention of Augustus. Imprisoned by Augustus as an incentive to hasten his research, Böttger was obliged to work with other alchemists in the futile search for transmutation and was eventually assigned to assist Tschirnhaus.^[10] One of the first results of the collaboration between the two was the development of a red stoneware that resembled the red stoneware of Yixing.

A workshop note records that the first specimen of hard, white and vitrified European porcelain was produced in 1708. At the time, the research was still being supervised by Tschirnhaus; however, he died in October of that year. It was left to Böttger to report to Augustus in March 1709 that he could make porcelain. For this reason, credit for the European discovery of porcelain is traditionally ascribed to him rather than Tschirnhaus.^[18]

The Meissen factory was established in 1710 after the development of a kiln and a glaze suitable for use with Böttger's porcelain, which required firing at temperatures up to 1,400 °C (2,552 °F) to achieve translucence. Meissen porcelain was once-fired, or green-fired. It was noted for its great resistance to thermal shock; a visitor to the factory in Böttger's time reported having seen a white-hot teapot being removed from the kiln and dropped into cold water without damage. Evidence to support this widely disbelieved story was given in the 1980s when the procedure was repeated in an experiment at the Massachusetts Institute of Technology.^{[citation needed]}

Soft paste porcelain

Saint-Cloud manufactory soft porcelain bowl, with blue decoration under glaze, 1700-1710.

Main article: Soft-paste porcelain

The pastes produced by combining clay and powdered glass (frit) were called Frittenporzellan in Germany and frita in Spain. In France they were known as pâte tendre and in England as "soft-paste".^[19] They appear to have been given this name because they do not easily retain their shape in the wet state, or because they tend to slump in the kiln under high temperature, or because the body and the glaze can be easily scratched.

Experiments at Rouen produced the earliest soft-paste in France, but the first important French soft-paste porcelain was made at the Saint-Cloud factory before 1702. Soft-paste factories were established with the Chantilly manufactory in 1730 and at Mennecy in 1750. The Vincennes porcelain factory was established in 1740, moving to larger premises at Sèvres^[20] in 1756. Vincennes soft-paste was whiter and freer of imperfections than any of its French rivals, which put Vincennes/Sèvres porcelain in the leading position in France and throughout the whole of Europe in the second half of the 18th century.^[21]

The first soft-paste in England was demonstrated by Thomas Briand to the Royal Society in 1742 and is believed to have been based on the Saint-Cloud formula. In 1749, Thomas Frye took out a patent on a porcelain containing bone ash. This was the first bone china, subsequently perfected by Josiah Spode.

In the fifteen years after Briand's demonstration, half a dozen factories were founded in England to make soft-paste table-wares and figures:

• Chelsea (1743)^[22][23]
• Bow (1745)^[24][25][26]
• St James's (1748)^[26][27]
• Bristol porcelain (1748)
• Longton Hall (1750)^[28]
• Derby (1757)^[29][30]
• Lowestoft porcelain (1757)^[31][32]

Other developments

William Cookworthy discovered deposits of kaolin clay in Cornwall, making a considerable contribution to the development of porcelain and other whiteware ceramics in the United Kingdom. Cookworthy's factory at Plymouth, established in 1768, used kaolin clay and china stone to make porcelain with a body composition similar to that of the Chinese porcelains of the early eighteenth century.

Types of porcelain

Ming Dynasty porcelain vase from the Wanli Emperor reign (1572-1620)

Demonstration of the translucent quality of porcelain

Porcelain can be divided into the three main categories: hard-paste, soft-paste and bone china depending on the composition of the paste, the material used to form the body of a porcelain object and the firing conditions.

Hard paste

Main article: Hard-paste porcelain

These porcelain that came from East Asia, especially China, were some of the finest quality porcelain wares. The earliest European porcelains were produced at the Meissen factory in the early 18th century; they were formed from a paste composed of kaolin and alabaster and fired at temperatures up to 1,400 °C (2,552 °F) in a wood-fired kiln, producing a porcelain of great hardness, translucency, and strength.^[11] Later, the composition of the Meissen hard paste was changed and the alabaster was replaced by feldspar and quartz, allowing the pieces to be fired at lower temperatures. Kaolinite, feldspar and quartz (or other forms of silica) continue to provide the basic ingredients for most continental European hard-paste porcelains.

Soft paste

Main article: Soft-paste porcelain

Soft-paste porcelains date back from the early attempts by European potters to replicate Chinese porcelain by using mixtures of clay and ground-up glass (frit) to produce soft-paste porcelain. Soapstone and lime were known to have been included in these compositions. These wares were not yet actual porcelain wares as they were not hard and vitrified by firing kaolin clay at high temperatures. As these early formulations suffered from high pyroplastic deformation, or slumping in the kiln at raised temperature, they were uneconomic to produce and of low quality. Formulations were later developed based on kaolin clay with quartz, feldspars, nepheline syenite or other feldspathic rocks. These were technically superior and continue in production. Soft-paste porcelains are fired at lower temperatures than hard-paste porcelain, therefore these are in general less hard than hard-paste porcelains.^[33][34]

Bone

Main article: Bone China

Although originally developed in England since 1748^[35] to compete with imported porcelain, bone china is now made worldwide. The English had read the letters, which describes in detail the Chinese porcelain manufacture secrets, given by Jesuit missionary Francois Xavier d'Entrecolles with avidity and one wild speculation was that a misunderstanding of the text was responsible for the first attempts to use bone-ash as an ingredient of English porcelain.^[36] In China, kaolin clay was sometimes described as forming the bones of the paste, while the flesh was provided by the refined rocks suitable for the porcelain body.^[36][33] Traditionally English bone china was made from two parts of bone-ash, one part of kaolin clay and one part china stone (a feldspathic rock), although this has largely been replaced by feldspars from non-UK sources.^[37]

Other uses

Electric insulating material

Porcelain insulator for medium-high voltage

Porcelain is an excellent insulator for use at high voltage, especially in outdoor applications. Examples are: terminals for high voltage cables, bushings of power transformers, insulation of high frequency antennas and many other cases.

Building material

Dakin Building, Brisbane, California using porcelain panels

Porcelain can be used as a building material, usually in the form of tiles or large rectangular panels. Modern porcelain tiles are generally produced to a number of recognised international standards and definitions.^[38][39] Manufacturers are found across the world^[40] with Italy being the global leader, producing over 380 million square metres in 2006.^[41] Historic examples of rooms decorated entirely in porcelain tiles can be found in several European palaces including ones at Capodimonte, Naples, the Royal Palace of Madrid and the nearby Royal Palace of Aranjuez.^[42] and the Porcelain Tower of Nanjing in China. More recent noteworthy examples include The Dakin Building in Brisbane, California and the Gulf Building in Houston, Texas which, when constructed in 1929, had a 70-foot-long (21 m) porcelain logo on its exterior.^[43] A more detailed description of the history, manufacture and properties of porcelain tiles is given in the article “Porcelain Tile: The Revolution Is Only Beginning.”^[43]

Manufacturers

This is an incomplete list, which may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries.

• For Austria, Denmark, Finland, Hungary, Lithuania, Poland, Norway, Poland, Romania, Spain, and Switzerland see Porcelain manufacturing companies in Europe

• Italy
  • Richard-Ginori 1735 Manifattura di Doccia, (1735-present)

• Hungary
  • Herend Porcelain Manufacture, (1826-present)
  • Hollóháza Porcelain Manufacture, (1777,1831-present)
  • Zsolnay Porcelain Manufacture, (1853-present)

• Germany
  • Current porcelain manufacturers in Germany

• Portugal
  • Vista Alegre

• France
  • Rouen porcelain, (1673–1696), faience
  • Nevers porcelain, (1600–1789), faience
  • Saint-Cloud porcelain, (1693–1766)
  • Chantilly porcelain, (1730–1800)
  • Vincennes porcelain, (1740–1756)
  • Mennecy-Villeroy porcelain, (1745–1765)
  • Sèvres porcelain, (1756–present)
  • Limoges porcelain, (1771–present)
  • Revol porcelain, (1789–present)
  • Haviland porcelain

• Japan
  • Narumi
  • Noritake

• Russia
  • Imperial Porcelain Factory (1744), Oranienbaum
  • Gzhel (ceramics) (1802), Gzhel (village)

• Turkey
  • Kutahya Porselen

• United Kingdom
  • Belleek
  • Chelsea porcelain factory
  • Coalport
  • Davenport
  • Goss crested china
  • Josiah Spode
  • Josiah Wedgwood
  • Liverpool porcelain
  • Mintons Ltd
  • New Hall porcelain
  • Plymouth Porcelain
  • Rockingham Pottery
  • Royal Crown Derby
  • Royal Doulton
  • Royal Worcester

• United States
  • Blue Ridge
  • Franciscan
  • Lenox
  • Lotus Ware

• Brazil
  • Germer Porcelanas Finas
  • Porcelana Schmidt

• Iran
  • Zarin porcelain

• Vietnam
  • Minh Long I porcelain

See also

• Lithophane
• Sea pottery
• Faience

References

1. ^ Oxford English Dictionary: "The ceramic material was apparently so named on account of the resemblance of its translucent surface to the nacreous shell of the mollusc. [...] The cowrie was probably originally so named on account of the resemblance of the fissure of its shell to a vulva (it is unclear whether the reference is spec. to the vulva of a sow)."
2. ^ OED, "China"; An Introduction to Pottery. 2nd edition. Rado P. Institute of Ceramic / Pergamon Press. 1988. Usage of "china" in this sense is inconsistent, & it may be used of other types of ceramics also.
3. ^ Birmingham Museum of Art (2010). Birmingham Museum of Art : guide to the collection. [Birmingham, Ala]: Birmingham Museum of Art. pp. 27. ISBN 9781904832775. http://artsbma.org. 
4. ^ ^{a b} Kelun, Chen (2004). Chinese porcelain: Art, elegance, and appreciation. San Francisco: Long River Press. p. 3. ISBN 9781592650125. http://books.google.com/books?id=zOEfZtcSaFEC. 
5. ^ ^{a b} "Porcelain". Columbia Encyclopedia Sixth Edition. 2008. http://www.encyclopedia.com/topic/porcelain.aspx#3. Retrieved 2008-06-27. 
6. ^ ^{a b} Te-k'un, Cheng (1984). Studies in Chinese ceramics. Hong Kong: Chinese University Press. pp. 92–93. ISBN 9789622013087. http://books.google.com/books?id=3die4xQmNzQC. 
7. ^ Adshead, S.A.M. (2004). T'ang China: The Rise of the East in World History. New York: Palgrave Macmillan. ISBN 1-4039-3456-8 (hardback). Page 80 & 83.
8. ^ ^{a b c d} Temple, Robert K.G. (2007). The Genius of China: 3,000 Years of Science, Discovery, and Invention (3rd edition). London: André Deutsch, pp. 104-5. ISBN 9780233002026
9. ^ Cohen, David Harris; Hess, Catherine (1993). Looking at European ceramics : a guide to technical terms. Malibu: The J. Paul Getty Museum Journal. p. 59. ISBN 9780892362165. http://books.google.com/books?id=PLAh5fomv2cC. 
10. ^ ^{a b} Burns, William E. (2003). Science in the enlightenment: An encyclopedia. Santa Barbara: ABC-Clio. pp. 38–39. ISBN 9781576078860. http://books.google.com/books?id=4H9_Zvp80nAC. 
11. ^ ^{a b c} Richards, Sarah (1999). Eighteenth-century ceramic: Products for a civilised society. Manchester: Manchester University Press. pp. 23–26. ISBN 9780719044656. http://books.google.com/books?id=vgoNAQAAIAAJ. 
12. ^ Wardropper, Ian (1992). News from a radiant future: Soviet porcelain from the collection of Craig H. and Kay A. Tuber. Chicago: Art Institute of Chicago. ISBN 9780865591066. http://books.google.com/books?id=E-J_fF8zgpMC. 
13. ^ Baghdiantz McAbe, Ina (2008). Orientalism in Early Modern France. Oxford: Berg Publishing, p. 220. ISBN 9781845203740
14. ^ Finley, Robert (2010). The pilgrim art. Cultures of porcelain in world history. University of California Press, p. 18. ISBN 9780520244689
15. ^ Kerr, R. & Wood, N. (2004). Joseph Needham : Science and Civilisation in China, Volume 5 Chemistry and Chemical Technology : Part 12 Ceramic Technology. Cambridge University Press, p. 36-7. ISBN 0521838339
16. ^ Zhang, Xiping (2006). Following the steps of Matteo Ricci to China. Beijing: China Intercontinental Press. p. 168. ISBN 9787508509822. http://books.google.com/books?id=o_u2P83LgGUC. 
17. ^ Burton, William. Porcelain, Its Nature, Art and Manufacture. London. pp. 47–48. http://www.archive.org/stream/cu31924089530079#page/n59/mode/2up/. 
18. ^ Gleeson, Janet. The Arcanum, an accurate historic novel on the greed, obsession, murder and betrayal that led to the creation of Meissen porcelain. Bantam Books, London, 1998.
19. ^ Honey, W.B., European Ceramic Art, Faber and Faber, 1952, p.533
20. ^ Munger, Jeffrey (October 2004). "Sèvres Porcelain in the Nineteenth Century". In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art. Retrieved 31 October 2011
21. ^ Metropolitan Museum of Art
22. ^ ‘Science Of Early English Porcelain.’ I.C. Freestone. Sixth Conference and Exhibition of the European Ceramic Society. Vol.1 Brighton, 20–24 June 1999, p.11-17
23. ^ ‘The Sites Of The Chelsea Porcelain Factory.’ E.Adams. Ceramics (1), 55, 1986.
24. ^ "Bow". Museum of London. http://www.museumoflondon.org.uk/ceramics/pages/subcategory.asp?subcat_id=725. Retrieved 31 October 2011. 
25. ^ "Bow porcelain bowl, painted by Thomas Craft". British Museum. http://www.britishmuseum.org/explore/highlights/highlight_objects/pe_mla/b/bow_porcelain_bowl,_painted_by.aspx. Retrieved 31 October 2011. 
26. ^ ^{a b} "Bow porcelain". British History Online. University of London & History of Parliament Trust. http://www.british-history.ac.uk/report.aspx?compid=22166. Retrieved 31 October 2011. 
27. ^ "St James's (Charles Gouyn)". Museum of London. http://www.museumoflondon.org.uk/ceramics/pages/subcategory.asp?subcat_id=727&subcat_name=St+James%27s+%28Charles+Gouyn%29. Retrieved 31 October 2011. 
28. ^ Ceramic Figureheads. Pt. 3. William Littler And The Origins Of Porcelain In Staffordshire. Cookson Mon. Bull. Ceram. Ind. (550), 1986.
29. ^ "History". Royal Crown Derby. http://www.royalcrownderby.co.uk/history. Retrieved 1 November 2011. 
30. ^ History of Royal Crown Derby Co Ltd, from "British Potters and Potteries Today", publ 1956^{[dead link]}
31. ^ 'The Lowestoft Porcelain Factory, and the Chinese Porcelain Made for the European Market during the Eighteenth Century.' L. Solon. The Burlington Magazine. No. 6. Vol.II. August 1906.
32. ^ Norfolk Museums & Archaeology Service^{[dead link]}
33. ^ ^{a b} Reed, Cleota; Skoczen; Stan (1997). Syracuse China. Syracuse, N.Y.: Syracuse University Press. pp. 51–52. ISBN 9780815604747. http://books.google.com/books?id=O4DcYxsoKjwC. 
34. ^ N. Hudson Moore (1903). The Old China Book. p. 7. ISBN 9781434477279. http://books.google.com/books?id=1W96CstNfEgC. 
35. ^ Strumpf, Faye (2000). Limoges boxes: A complete guide. Iola, WI: Krause Publications. p. 125. ISBN 9780873418379. http://books.google.com/books?id=RKaRJHFUK-wC. 
36. ^ ^{a b} Burton, William. Porcelain, Its Nature, Art and Manufacture. London. pp. 18–19. http://www.archive.org/stream/cu31924089530079#page/n31/mode/2up. 
37. ^ Changes & Developments Of Non-plastic Raw Materials. Sugden A. International Ceramics Issue 2 2001.
38. ^ “New American Standard Defines Polished Porcelain By The Porcelain Tile Certification Agency.” Tile Today No.56, 2007.
39. ^ Porcelain tile as defined in ASTM C242 - 01(2007) Standard Terminology of Ceramic Whitewares and Related Products published by ASTM International.
40. ^ ’Manufacturers Of Porcelain Tiles’ Ceram.World Rev. 6, No.19, 1996 … ‘The main manufacturers of porcelain tiles in Italy, Europe, Asia, Africa, Oceania and the Americas are listed.’
41. ^ ”Italian Porcelain Tile Production At The Top” Ind.Ceram. 27, No.2, 2007.
42. ^ Porcelain Room, Aranjuez Comprehensive but shaky video
43. ^ ^{a b} “Porcelain Tile: The Revolution Is Only Beginning.” Tile Decorative Surf. 42, No.11, 1992.

Further reading

• Combined Nomenclature of the European Communities - EC Commission in Luxembourg, 1987 .
• Burton, William (1906). Porcelain, its Nature, Art and Manufacture. Batsford, London

External links

Wikimedia Commons has media related to: Porcelain

• How porcelain is made
• How bisque porcelain is made
• International Ceramic Directory - providing you with links to ceramic artists, backstamps, manufacturers, historical sites and more
• ArtLex Art Dictionary - Porcelain

v d e Porcelain China Chinese porcelain · Chinese export porcelain · Chinese influences on Islamic pottery Types: Proto-celadon (16th century BCE) · Celadon (1st century) · Yue (2nd century) · Jingdezhen (6th century) · Sancai (8th century) · Ding (10th century) · Qingbai (12th century) · Blue and white (14th century) · Blanc de Chine (14th century) · Kraak (16th century) · Swatow (16th century) · Kangxi (17th century) · Famille jaune, noire, rose, verte (17th century) · Tenkei (17th century) · Canton (18th century) Korea Korean porcelain Types: Goryeo (10th century) · Joseon (14th century) Japan Japanese porcelain Types: Imari (17th century) · Kakiemon (17th century) · Kutani (17th century) Europe French porcelain · Chinese porcelain in European painting Types: Fonthill Vase (1338) · Medici (1575) · Rouen (1673) · Nevers · Saint-Cloud (1693) · Meissen (1710) · Chantilly (1730) · Vincennes (1740) · Chelsea (1743) · Oranienbaum (1744) · Mennecy (1745) · Bow (1747) · Nymphenburg Porcelain Manufactory (1747)  · Plymouth (1748) · Worcester (1751) · Frankenthal Porcelain Factory (1755)  · Sèvres (1756) · Derby (1757) · Wedgwood (1759)  · Wallendorf (1764)  · Etiolles (1770) · Limoges (1771) · Clignancourt (1775) · Royal Copenhagen (1775)  · Revol (1789)  · Herend Porcelain Manufactory (1826)  · Zsolnay (1853) Technologies Soft-paste porcelain · Hard-paste porcelain · Bone china · Factory mark People Ehrenfried Walther von Tschirnhaus · Johann Friedrich Böttger · Francois Xavier d'Entrecolles · Dmitry Vinogradov Collections British Museum (London): Asia Department / Percival David Foundation · Dresden Porcelain Collection · Gardiner Museum (Toronto) · Kuskovo State Museum of Ceramics (Moscow) · Musée national de Céramique-Sèvres (Paris) · Musée des Arts Décoratifs (Paris) · Palace Museum (Beijing) · Topkapı Palace (Istanbul) · Victoria and Albert Museum (London) · Worcester Porcelain Museum

v d e Pottery List of pottery terms Materials Earthenware Stoneware Porcelain Ball clay Bentonite Terracotta Ash glaze Techniques Pinching Coiling Wheel throwing Processes Burnishing RAM pressing Slipcasting Glazing Firing Bisque firing Saggar firing Pit firing Products Studio pottery Salt glaze pottery Delftware Ceramics of indigenous peoples of the Americas Harvest jug Iranian pottery Kakiemon Poole Pottery Jasperware Korean ceramics Mexican ceramics Rockingham Pottery Sea pottery Slipware Notable potters Potters by nationality

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Dansk (Danish)
n. - porcelæn

Nederlands (Dutch)
porselein, porseleinen

Français (French)
n. - porcelaine

Deutsch (German)
n. - Porzellan

Ελληνική (Greek)
n. - πορσελάνη
adj. - πορσελάνινος

Italiano (Italian)
porcellana, di porcellana

Português (Portuguese)
n. - porcelana (f)
adj. - de porcelana

Русский (Russian)
фарфор

Español (Spanish)
n. - porcelana, de porcelana

Svenska (Swedish)
n. - porslin
adj. - porslins-

中文（简体）(Chinese (Simplified))
瓷器, 瓷

中文（繁體）(Chinese (Traditional))
n. - 瓷器, 瓷

한국어 (Korean)
n. - 자기, 자기제품

日本語 (Japanese)
n. - 磁器, 磁器製品

العربيه (Arabic)
‏(الاسم) خزف صيني (صفه) صيني‏

עברית (Hebrew)
n. - ‮חרסינה, כלי חרסינה‬

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