Underglaze

Beaker-Shaped Vase with Four Animals, porcelain with underglaze blue at The Walters Art Museum

Ming dynasty Xuande mark and period (1426–35) imperial blue and white vase. The Metropolitan Museum of Art, New York. 明宣德 景德鎮窯青花貫耳瓶, 纽约大都博物馆

Underglaze is a method of decorating ceramic articles in which the decoration is applied to the surface before it is glazed. Because the glaze will subsequently cover it, such decoration is completely durable, and it also allows the production of pottery with a surface that has a uniform sheen. Underglaze decoration uses pigments derived from oxides which fuse with the glaze when the piece is fired in a kiln. However, because the glost firing is at a higher temperature than used in on-glaze decoration, the range of available colours is more limited. Examples of oxides that do not lose their colour during a glost firing are the cobalt blue made famous by Chinese Ming dynasty blue and white porcelain and the cobalt and turquoise blues, pale purple, sage green, and bole red characteristic of İznik pottery.

References

• Fournier, Robert, Illustrated Dictionary of Practical Pottery (Van Nostrand Reinhold, 1973) ISBN 0-442-29950-8
• Hamer, Frank, and Hamer, Janet, The Potter's Dictionary of Materials and Techniques (A&C Black/University of Pennsylvania Press, 2004) ISBN 0-8122-3810-9

External links

• More about underglaze blue printing in the North Staffordshire pottery industry