Porcelain single operation. In this process, "green" (unfired) ceramic wares are heated to high temperatures in a kiln to permanently set their shapes. Porcelain is fired at a higher temperature than earthenware so that the body can vitrify and become non-porous. Porcelain originated in China, and it took a long time to reach the modern material. Until recent times, almost all East Asian porcelain was of the hard-paste type. There is no precise date to separate the production of proto-porcelain from that of porcelain. Although proto-porcelain wares exist dating from the Shang dynasty (1600–1046 BC), by the time of the Eastern
Biscuit porcelain by giving them a temporary coating of wax or something similar to keep the glaze off; this is a fairly common feature of Longquan celadon (which is porcelain in Chinese terms), and also found in Ming dragons. Some Chinese pieces are described as "porcelain with polychrome enamels on the biscuit" - that is, using the normal "overglaze" technique on biscuit, but with no actual glaze, often a revivalist style evoking earlier sancai wares (which were not in porcelain). The laborious and mostly 19th-century pâte-sur-pâte technique often uses biscuit for at least one of the colours. Biscuit porcelain Biscuit porcelain, bisque