4 ideas
Augustus the Strong of Saxony held the young alchemist Johann Friedrich Böttger captive and ordered him to make gold. Working with the scholar Ehrenfried Walther von Tschirnhaus, Böttger instead produced the first European hard-paste porcelain around 1708–09.
True porcelain needs two Chinese materials. Kaolin, a white clay named after Gaoling hill near Jingdezhen, is the bones. Petuntse, a feldspathic china stone, is the flesh.
Heinrich Himmler's SS ran a porcelain manufactory at Allach, near Munich, and used prisoners from nearby Dachau as labour. It produced white figurines, Yule candle-holders and other objects of Nazi ritual. These were presented as emblems of Germanic purity while being produced by people the regime was working to death. The ideal of flawless whiteness and the cruelty of its production sat in the same place.
It got out because arcanists such as Samuel Stöltzel took the knowledge with them. Craft knowledge lives in hands and memory rather than documents, so any monopoly built on it lasts only as long as its holders can be kept from leaving.