Doucai is the Ming dynasty porcelain decoration that combines underglaze blue with colored overglaze enamels.
The technique usually begins with an outline or portions of the design painted in cobalt blue beneath the glaze. After an initial firing, additional colors are applied over the glazed surface and fired again at a lower temperature. The result is a layered design in which blue underglaze lines work with red, green, yellow, and other overglaze colors.
Doucai became particularly associated with refined imperial porcelains of the Chenghua era in the fifteenth century. Small cups and other vessels from this period are among the most famous examples, and surviving pieces are highly prized by museums and collectors.
Doucai means “joined colors.” It differs from wucai, which generally uses several overglaze colors with less emphasis on an underglaze-blue outline, and from famille rose, a later Qing palette dominated by opaque pink enamels.