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
Jingdezhen porcelain were appointed by the provincial administration up until 1726, when Beijing appointed Nian Xiyao. Wares of this interim period are often called "Transitional", and include the Tianqi porcelain mostly made for the Japanese market. The effect on the Jingdezhen potters was "liberating", as the range of subject matter in decoration greatly expanded. Printed books had become much more widely available, and were used, directly or indirectly, as sources for scenes on porcelain. Conveniently for the historian, many pieces began to be dated. Towards the end of the period the first "famille rose" porcelains appeared; the various colour "families" were to