Book: Ceramics - Art or Science? Author: Dr. Stan Jones

7. Pottery Technology 1

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7.13 Faience

Archaic faience is not to be confused with the, much later, tin-glazed earthenware pottery of the same name, made famous in France, Spain and Renaissance Italy (also called Majolica). The archaic faience body was made predominantly from crushed quartz or sand, with small amounts of lime, sodium carbonate (natron) and alkaline potash (plant ash), sometimes powdered talc, and, initially, copper as colourant (natural malachite or blue azurite). Water was added, making a thixotropic mixture (viscous initially, but less so as worked), so shaping the body was difficult – imagine modelling with wet sand into a shape! Other methods were used, such as finely grinding and mixing the “glaze” ingredients first, then mixing with water into a slurry and applying it to the preformed body where it seeps in. In drying, the salts migrate to the surface so that when fired the soda-lime-silicate mixture from the non-quartz ingredients vitrifies and forms the continuous visible outer blue or green glaze. Internally there is more haphazard fusing that “glues” a proportion of the quartz grains together. Whether the resultant is a glass or a ceramic or neither is debatable, but it is certainly decorative and was used instead of the much more “expensive” semi-precious stones, lapis lazuli or turquoise.

Egyptian Faience, Toy Cup UC17512, Man Playing Pipes UC16684 and Toy Ball UC21097 - copyright of the Petrie Museum of Egyptian Archaeology, UCL

Egyptian Faience, Toy Cup UC17512, Man Playing Pipes UC16684
and Toy Ball UC21097 - copyright of the Petrie Museum of
Egyptian Archaeology, UCL

A related product was achieved by coating steatite (soapstone or hydrous magnesium silicate) items with the same glaze material, then firing them. Soapstone is very easy to work and withstands heat without cracking, being converted to an anhydrous form at 1050 degrees C. Faience was produced in large quantities and perhaps the most notable countries making it were Egypt, Crete and the Indus valley. Apparently some examples even reached Ancient Britain.

7.14 Majolica

Majolica is a relatively soft porous earthenware having a thick tin-glaze (30 to 300 microns) and it is usually highly decorated. It was first produced in the Middle East, and the Islamic Muslims then spread the technology across North Africa to Spain in 712 AD and over time to the rest of Europe. There is a particular difficulty in painting a tin-glazed item such as Majolica, because of the glaze’s porosity. The opaque glaze would be applied to the biscuit fired body, dried, then the enamels had to be applied very carefully to the absorbent surface – no corrections were possible. The golden age of majolica coincided with the Renaissance era in Italy, but it continues to be made to the present. At the best these highly decorative wares are effectively “Old Master” paintings on pottery rather than canvas, and are decorated with biblical and mythological scenes or as portraits.

Istoriata Majolica - source Wikipedia

Istoriata Majolica - source Wikipedia

Tiled Mihrab Niche 1432 AD - source Museum Istanbul

Tiled Mihrab Niche 1432 AD
- source MuseumIstanbul

Sometimes a lower temperature lead glaze was added to the tin-glazed item after the second firing to enhance the gloss, requiring a third lower temperature firing to carried out. Many of the technological advances needed, such as the new colours and the skills to paint on the pre-fired surface, were further developed in Italy in the middle of the 15th century. Majolica suited itself to ceramics of all shapes and sizes – from tiles to sculptures.

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