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
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