Underglaze

Underglaze is a method of decorating ceramic articles, the decoration is applied to the surface before it is glazed. Because the glaze will subsequently cover it such decoration is completely durable, but because the subsequent glost firing is at a higher temperature than used in on-glaze decoration the range of available colours is more limited. It uses pigments derived from oxides which fuse with the glaze when the piece is fired in a kiln. Examples include Blue and white porcelain and İznik pottery.