ceramics conservation, ceramic conservation
Unglazed stoneware vase, John Flaxman, about 1780. Museum no. 2416-1901
Jasperware vase and cover
John Flaxman
Wedgwood
England
About 1780
Unglazed stoneware
Museum no. 2416-1901
Stoneware is fired at a high temperature (around 1200º-1300ºC) and varies in colour from light grey to dark red, depending on the clay. It has a strong, non-porous body. Stoneware can be unglazed or glazed - this example is unglazed stoneware.
Glazed stoneware wine pot, 1100-50. Museum no. C.527-1918
Wine pot
Koryo dynasty, Korea
1100-50
Celadon glazed stoneware
Museum no. C.527-1918
Stoneware is fired at a high temperature (around 1200º-1300ºC) and varies in colour from light grey to dark red, depending on the clay. It has a strong, non-porous body. Stoneware can be unglazed or glazed - this example is glazed stoneware.
Glazed earthenware dish, 1655-65. Museum no. C.248-1911
Earthenware dish
London
1655-65
Tin glazed
Museum no. C.248-1911
Earthenware is fired at comparatively low temperatures (up to 1150ºC) and ranges in colour from creamy-white to red-brown. The low firing temperature means that the clay particles are only partly fused together and there are spaces (pores) between them. Earthenware is prone to staining, because liquids are able to penetrate into the body through the pores. Earthenware pieces tend to have thicker walls than stoneware and porcelain, to add strength. Earthenware objects may be unglazed or glazed.
Hard-paste porcelain dish, 1644 - 1911.
Museum no. 491-1931
Porcelain dish
Chinese Qing
1644 - 1911
Hard-paste decorated in underglaze cobalt blue
Museum no. 491-1931
Porcelain describes ceramics with a white body fired at a high temperature.
Hard-paste porcelain, also known as true porcelain, is fired at temperatures up to 1450ºC. It has a vitrified (glassy) appearance and is hard, strong and non-porous. It can be used to make very delicate objects which may be thin walled and translucent. The glaze on hard-paste porcelain is fused to the body by the high firing temperature. Exposed or broken edges can be very smooth and almost glassy in texture. Hard-paste porcelain is made from china stone and/or china clay (kaolin).
Soft-paste porcelain plate, about 1765. Museum no. 528-1902
Porcelain plate
Chelsea
England
About 1765
Soft-paste decorated in enamel colours with gold anchor mark
Museum no. 528-1902
Porcelain describes ceramics with a white body fired at a high temperature.
Soft-paste porcelains were made in Europe in imitation of East Asian porcelains. Soft-paste porcelain has a softer body than hard-paste porcelain and is slightly porous. The glaze is fired at a lower temperature than the body and sits on it as a distinct layer. Often on soft-paste porcelain the colours appear to sink into the glaze.
Bone china porcelain plate, about 1897. Museum no. Circ.70-1970.
Bone china
Minton & Co, Stoke on Trent
England
About 1897
Transfer printed with enamel painting
Museum no. Circ.70-1970
Porcelain describes ceramics with a white body fired at a high temperature.
Bone china is a porcellanous body developed in the eighteenth century in Staffordshire and is still produced today. It contains a high proportion of bone ash in combination with china clay and china stone.
Biscuit porcelain figure, Étienne-Maurice Falconet, about 1764-66. Museum no. 382-1874
Figure of Leda and the Swan
Étienne-Maurice Falconet, Sèvres
France
About 1764-66
Biscuit porcelain
Museum no. 382-1874
Porcelain describes ceramics with a white body fired at a high temperature.
Biscuit porcelain refers to porcelain that is fired but left unglazed.
Parian porcelain figure, John Bell, 1847. Museum no. 44-1865
Figure of Dorothea
John Bell
Minton & Co., Stoke-on-Trent
England
1847
Parian porcelain
Museum no. 44-1865
Porcelain describes ceramics with a white body fired at a high temperature.
Parian refers to fine-grained porcelain, usually unglazed, that imitates marble. It became popular from the mid 19th century, especially for making figures and busts.