Royal Dux

1918 - 1930 1918 - 1930     (not a registered trademark) Appears mostly on porcelain items.Stamp is blue on glaze.	1918-1930   1918 - 1930   You can find this stamp mostly on plaque's and sometimes on porcelain, stamp is either green, black or blue.
1918-1938 1918-1938   After 1918 the Made in Czechoslavakia stamp was added most of the time it was acompanied by the raised triangle	1918-1945
1938-1945	1918-1945
1926-1951	1918-1980
1960-1978	1945 - 1978 In pink or blue we have to date the stamp from 1945 - 1990 untill further research is complete.
1951 - Present	1945-1951
1974-1978	1970-1992
1953-1992	1992-present In 1992 chechoslavkia became czech republic