I haven't been there for quite a few years but it is a great city. I ended up spending a great deal of time in Novy Bor, about 40-50KM from Prague. They had a couple of glass factories in that area and a couple of good galleries. They also have an exhibit of glass that has been made during the IGS, International Glass Symposiums at castle Lemberk. They also had a glass museum in Novy Bor and another in Kamenicky Senov. I attended the IGS in 1997 and it was amazing. The Crystalex factory was there, Eggermann factory and Ajeto, Lindava, factory as well. They also had a secondary glass school there and several galleries. The exhibit at the castle highlights pieces made by some of the very best in the last 30 years of contempoary glass from many countries. I would check to see that nay of these places are still open as I have not been there for many years and things change.