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Porcelain & Porcelain BisquePorcelain is a type of hard pottery. It is white, but mildly transluscent and can be decorated to provide colour. When glazed it has a smooth and glossy finish.
Porcelain bisque is unglazed porcelain: white and slightly porous, with a matte finish. Porcelain Bisque is often used for high-quality dolls and figurines, with the features hand painted. See Snowbabies for examples of porcelain bisque figurines. Snowbabies are cute little babies in white snow suits. They live in Frosty Frolic Land, along with animal friends such as penguins, polar bears, seals, and walruses. Chinese PorcelainChinese porcelain is made from a hard paste comprised of the clay kaolin and a feldspar called petuntse, which cements the vessel and seals any pores. China is high-quality porcelain. Most china comes from the city of Jingdezhen in China's Jiangxi province.Jingdezhen, under a variety of names, has been central to porcelain production in China since at least the early Han Dynasty. Earliest techniques were very primitive, barely above the level of mere pottery. By the time of the Southern and Northern Dynasty period, however, techniques had been refined to the point that the clay in Jingdezhen made for what could be called porcelain. The Sui and Tang Dynasties introduced high-temperature kilns, bringing with it the pure, translucent whites, attractive to the eye, as well as a variety of advanced glazing techniques resulting in smooth, durable porcelain. The resulting product was often referred to as "false jade". European PorcelainThe Europeans used a soft paste, which makes for weaker porcelain than the Chinese method. To compensate, around 1750 the English began to use calcined bone ash to strengthen their porcelain, with the resulting material (typically comprising 25% to 50% bone ash) becoming known as bone china.TechniquesThe most noticeable difference between porcelain and the other pottery clays is that it 'wets' very quickly (that is, added water has a noticeably greater effect on the plasticity for porcelain than other clays), and that it tends to continue to 'move' for longer than other clays, requiring experience in handling to atain optimum results. 1. Mold, form, turn, wedge, cast or sculpt clay into the desired shape. Avoid air pockets. Slipcasting is probably the easiest technique for mass-production. A liquid clay slip is poured into plaster moulds and allowed to harden slightly. Once the plaster has absorbed most of the liquid from the outside layer of clay the remaining slip is poured back into the storage tub, and the item is left to dry. Finally the finished item is removed from the mould, trimmed neatly and allowed to air-dry. 2. Allow to air dry, slowly, until it is dry and hard to the touch. Once air-dried, the clay piece is called greenware. Items of greenware are very brittle but they can be handled with care. Greenware items are often sanded with fine grade sandpaper to ensure a smooth finish in the completed item. 3. Bisque (or biscuit) firing- Apply no glaze. Place the greenware into a kiln or similar furnace and
fire for about three days:- 4. Glazing is the process of coating the piece with a thin layer of a glassy material. This is important for functional vessels, which would otherwise be unsuitable for holding liquids due to porosity. Glaze may be applied by dusting it over the clay, or dipping or brushing on a thin slurry of glaze and water. Brushing tends not to give very even covering, but can be effective with a second coating of a colored glaze as a decorative technique. With all glazed items, a small part of the item (usually on the base of the piece) must be left unglazed, else it will stick to the kiln during firing. Glaze firing is similar to bisque firing, but requires a higher temperature, of around 1300°C (2300°F). Porcelain is typically biscuit fired at around 1000 degrees Celcius (1800 degrees Farenheight), and glaze fired (the final fireing) at around 1300°C (2300°F). See Snowbabies for examples of porcelain bisque figurines. Snowbabies are cute little babies in white snow suits. They live in Frosty Frolic Land, along with animal friends such as penguins, polar bears, seals, and walruses.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Porcelain" and from http://www.white-on.com
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Porcelain Bisque Snowbabies
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