Meissen porcelain further precaution, very few workers knew the special secret ("arcanum") of how to make porcelain, and then perhaps only part of the process. Thus, for a few years, Meissen retained its monopoly on the production of hard-paste porcelain in Europe. By 1717, however, a competing production was set up at Vienna, as Samuel Stöltzel sold the secret recipe, which involved the use of kaolin, also known as china clay. By 1760 about thirty porcelain manufacturers were operating in Europe, most of them, however, producing frit based soft-paste porcelain. In order to identify the original Meissen products, Meissen developed markings that
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