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
Liverpool porcelain was said to be known as the "Pottery Capital of the World" (at least in the American Mid-West). The factories included: Richard Chaffers made soapstone-type porcelain featuring mainly Oriental designs at Shaw's Brow. An advertisement for it in 1756 provides the earliest documentation of Liverpool porcelain production, which he continued until his death in 1765. In 1756 he also held a license to mine soapstone at a site in Cornwall. The porcelain resembles Worcester porcelain. Most of the plates made by the factory are octagonal, and some tea and coffee sets are six-sided. A common product was a bulbous mug