Thank you Coup. That is good to know.
I have two of Walthraud Neuwirth's books and they are truly absolutely excellent -
Farbenglas 1 (a present from Michael on this board, and which was such a good book I had to search to get Farbenglas 11 from Germany)
and
Farbenglas II
I love them and refer to them frequently and always refer to them if I have a query about Bohemian glass or particularly 19th century glass (although later glass is included as well).
I am interested in the development of colour in glass and they are indispensable for the incredible information they contain.
m