How is glass made?

The third method was casting, which called for pouring hot, molten glass into a mold. A variation on cast glass was faience, made from powdered quartz blended into molten glass. The mixture might be pressed between two molds to make a cast vessel such as a bowl.

Glassblowing. It was probably in the Middle East during the first century b.c.e. that the important technique of glassblowing was discovered. A hollow metal rod (or pipe) was used to pick up a gob of molten glass; the act of blowing into the pipe generated a bubble of glass. If the bubble were blown into a mold, the molten glass could be given a desired shape. Wooden paddles and pincers were used to refine the shape even further. The blowing procedure was used to make glass objects that were larger and thinner than those that had been made previously, and it was much faster than previous glass-forming methods. As glass pieces became easier to make, they became cheaper and more available. The ancient Romans became particularly skillful at glassblowing. More glass was produced and used in the Roman world than in any other civilization of antiquity. During the Middle Ages, there was a great expansion of glassblowing activity, especially in Venice, the Middle East, and European countries such as Spain and Germany.