Earthenware is the most porous of the three main types of ceramic ware, having a porosity of more than 5% after firing. Most of the clays used to make earthenware are only suitable for firing to a relatively low temperature, between 800-1100oC. After firing the ceramics are permeable, and vessels are therefore frequently glazed. The most common glazes used on Chinese earthenwares are lead-fluxed glazes. In China, earthenwares are designated tao to differentiate them from high-fired wares such as stoneware or porcelain.
A colored opaque glass or glaze-like substance that is bonded to a metal surface. In China, enamels can be applied to metal, ceramic or glass bodies. In ceramics, enamels may be applied either to a pre-fired, unglazed body, or painted onto the surface of a high-fired glaze, after which the object is fired a second time at a lower temperature. Overglaze enamels seem first to have appeared in China on stonewares made at the Cizhou kilns in the Song or Jin dynasties. Certain Chinese enamel colour palettes are known by specific names, such as wucai, yingcai, famille verte, famille noire, famille jaune, fencai, and famille rose.