Tin-glazing
From Wikipedia, the free encyclopedia
Tin-glazing is the process of giving ceramic items a tin-based glaze which is white, shiny and opaque.
Tin glazes, normally fired on red or buff earthenware, were invented by the Assyrians three thousand years ago. Tin-glazed ware became very popular from the 8th century, and spread through Spain in the 12th century before reaching Italy in the Renaissance, Holland in the 16th century and England and France shortly after. The tin-glazed ware from Spain is known as Hispano-Moresque, from Italy as maiolica, and from Holland as Delft. Faience is also tin-glazed.
Tin oxide (IV), has found widespread use in glaze, where it has been valued as an opacifier. Tin oxide can remain in suspension in the vitreous matrix, and, with its Refractive Index being sufficiently different to the matrix light is scattered, and hence increases the opacity of the glaze. Due to the high cost of tin oxide many glaze formulations now use other opacifiers, such as zircon
The earliest Middle Eastern tin glazes used lime, soda and potash as fluxes in combination with the silica in sand. Piccolpasso recorded several glazes used in Italy in the 1550s, all variations of lead, tin, lime, soda and potash glazes. It is believed early Spanish glazes were similar.[1] A typical modern tin-glaze recipe is given by Alan Caiger-Smith:[2]
- Lead bisilicate frit: 74%
- China clay: 10%
- Whiting: 2%
- Flint: 4%
- Tin oxide: 10%
Tin-glazed ware is almost always decorated, which its white surface lends itself to. The decoration, often multi-coloured, is applied to the unfired glaze surface, usually by brush, as metallic oxides, most commonly cobalt oxide, copper oxide, iron oxide, manganese dioxide and antimony oxide. Late Italian maiolica blended oxides to produce detailed and realistic polychrome paintings.
Tin-glaze fell out of use in the 18th century after Josiah Wedgwood formulated a very white earthenware body. There has been a revival in the twentieth century by studio potters. Picasso produced and designed a great deal of tin-glazed pottery and sculpture in Vallauris in the South of France in the 1940s and 1950s.
[edit] Bibilography
- Caiger-Smith, Alan, Tin-Glaze Pottery in Europe and the Islamic World: The Tradition of 1000 Years in Maiolica, Faience and Delftware (Faber and Faber, 1973) ISBN 0-571-09349-3
- Caiger-Smith, Alan, Lustre Pottery: Technique, Tradition and Innovation in Islam and the Western World (Faber and Faber, 1985) ISBN 0-571-13507-2
- Carnegy, Daphne, Tin-glazed Earthenware (A&C Black/Chilton Book Company, 1993) ISBN 0-7136-3718-8
- Harris, David, Guide To Looking At Italian Ceramics (J. Paul Getty Museum in association with British Museum Press, 1993)
- McCully, Marylin (ed.), Picasso: Painter and Sculptor in Clay (Royal Academy of Arts, 1998) ISBN 0-900-94663-6
- Piccolpasso, Cipriano, The Three Books of the Potter's Art (trans. A.Caiger Smith and R.Lightbown) (Scolar Press, 1980) ISBN 0-859-67452-5
