Glassmakers' symbol

The glassmaker's mark (rarely glassmaker's cross: ) is a symbol of glassmakers. It is a figure eight (infinity sign) over a sword or cross, illustrating a German glassmaker's saying: Es ist ein unendlich Kreuz, Glas zu machen ("it is an endless cross to make glass").

The symbol dates to 1948, when the magazine Glastechnischen Berichte displayed it on the cover. The figure eight was said to symbolize the material glass in its two phases, as a molten liquid on the left and as a non-crystalline solid on the right. In the transition between the two states, a metal sword, which stood for the glassmaker's pipe, was a sign of man's dominion over nature.

The German Technical Glass Society (Deutsche Glastechnische Gesellschaft) and the Czech Glass Society (Česká sklářská společnost) use the glassmaker's mark as the symbol of their associations.