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
Chelsea porcelain factory at least in the early period. The annual actions were partly intended for the chinamen, with some lots made up of a range of wares to provide a stock. The East India Company had been selling its cargos of East Asian porcelain at auction for some decades. Chelsea wares reached British America, but there were probably few exports to the Continent. Early English porcelain was soon being collected, especially in the late 19th century, when prices rose steadily. Over the 20th century there has been a great reversal in collectors' interests, with wares from later in the century far cheaper