Lithopanes were pictures (generally, a Japanese woman) that appear impressed on thin bottom of porcelain cups. It was made in Japan between the late 1930's and into the late 1950's/early 1960's, mostly for export. Many pieces dates to the "Occupied Japan" period (1945-52) and could thus be dated from their marks. Many are not marked at all or marked with no western characters. Most of these porcelains appears to have been made by the Kutani factory in Japan. See Jan-Erik Nilsson. "Lithopane". Gotheborg.com. Retrieved 2014-11-16.