Porcelain

The greater strength and translucence of porcelain, relative to other types of pottery, arise mainly from vitrification and the formation of the mineral mullite within the body at these high temperatures.

Porcelain slowly evolved in China and was finally achieved (depending on the definition used) at some point about 2,000 to 1,200 years ago.

[2] Properties associated with porcelain include low permeability and elasticity; considerable strength, hardness, whiteness, translucency, and resonance; and a high resistance to corrosive chemicals and thermal shock.

Porcelain has been described as being "completely vitrified, hard, impermeable (even before glazing), white or artificially coloured, translucent (except when of considerable thickness), and resonant".

[3] However, the term "porcelain" lacks a universal definition and has "been applied in an unsystematic fashion to substances of diverse kinds that have only certain surface-qualities in common".

[7] 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 constitute the basic ingredients for most continental European hard-paste porcelains.

The English had read the letters of Jesuit missionary François Xavier d'Entrecolles, which described Chinese porcelain manufacturing secrets in detail.

[11] One writer has speculated that a misunderstanding of the text could possibly have been responsible for the first attempts to use bone-ash as an ingredient in English porcelain,[11] although this is not supported by modern researchers and historians.

Other raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse and alabaster.

Porcelain often receives underglaze decoration using pigments that include cobalt oxide and copper, or overglaze enamels, allowing a wider range of colours.

In this process, "green" (unfired) ceramic wares are heated to high temperatures in a kiln to permanently set their shapes, vitrify the body and the glaze.

Porcelain was invented in China over a centuries-long development period beginning with "proto-porcelain" wares dating from the Shang dynasty (1600–1046 BCE).

[27] Exports to Europe began around 1660, through the Chinese and the Dutch East India Company, the only Europeans allowed a trading presence.

Nabeshima ware was produced in kilns owned by the families of feudal lords, and were decorated in the Japanese tradition, much of it related to textile design.

Imari ware and Kakiemon are broad terms for styles of export porcelain with overglaze "enamelled" decoration begun in the early period, both with many sub-types.

[28] A great range of styles and manufacturing centres were in use by the start of the 19th century, and as Japan opened to trade in the second half, exports expanded hugely and quality generally declined.

Additionally, in the late 13th century, the Inlay technique of expressing pigmented patterns by filling the hollow parts of pottery with white and red clay was frequently used.

Early in the 16th century, Portuguese traders returned home with samples of kaolin, which they discovered in China to be essential in the production of porcelain wares.

[7][36] In 1712, many of the elaborate Chinese porcelain manufacturing secrets 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.

[37] Von Tschirnhaus along with Johann Friedrich Böttger were employed by Augustus II, King of Poland and Elector of Saxony, who sponsored their work in Dresden and in the town of Meissen.

Tschirnhaus had a wide knowledge of 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, he claimed to have known the secret of transmuting dross into gold, which 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.

[38] 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 of up to 1,400 °C (2,552 °F) to achieve translucence.

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.

His development of porcelain manufacturing technology was not based on secrets learned through third parties, but was the result of painstaking work and careful analysis.

[citation needed] During the twentieth century, under Soviet governments, ceramics continued to be a popular artform, supported by the state, with an increasingly propagandist role.

[44] The pastes produced by combining clay and powdered glass (frit) were called Frittenporzellan in Germany and frita in Spain.

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.