Saturday, January 2, 1971

Ceramics

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• Ceramics made with porous paste: unglazed pottery, glazed pottery, faience. 
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The word faience comes from Faenza, an Italian ceramic production center of the XVIth century. Majolica exclusively designates Italian majolica. 
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“Tin-based” faience. After a bisque fire (900°), the clay piece is covered with a tin oxide glaze-based (enamel) which gives it its white color. The painted decoration is then applied after the enamel dries before the second firing called “the high fire” or glost fire. The “low fire” came later, in the XVIIIth century in Europe. It permitted colors that were less resistant to heat to be used during firing at a lower temperature (750°). One example is the famous red or purple of Cassius. 
Fine English faience is made of white clay. The glaze is lead-based and so is translucent and much less costly. 
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• Ceramics made with impermeable paste: stoneware, porcelain. 
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“Soft paste,” which was created in the late XVIIth century, attempted to compete with the hard porcelain imported from the Far East and whose manufacturing secrets were not known. It was in Meissen in Saxony that Nicolas Bottger, who discovered a deposit of kaolin, developed the hard porcelain technique in 1709. It did not appear in France until 1767. The porcelain object that undergoes an initial bisque fire is called biscuit. The decoration is then painted under or over a glaze derived from feldspath using either the high-fire or low-fire technique. Entirely vitrified at 1,400°, it is the only type of ceramics that cannot be penetrated by a steel point. 
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• Ceramics made with siliceous paste. 
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Specific to productions from the Middle East. The best known come from Iznik in Anatolia.