Khan Academy
Khan Academy: Glassmaking Technique: Mold Blown Glass
Mold-blown glass is made by blowing hot glass into a mold made of clay, wood, or metal. Watch a glassmaker use a mold with incised designs (footage [1:48] from the Corning Museum of Glass).
Khan Academy
Khan Academy: Roman Mold Blown Glass
Mold-blown glass is forced against the inner surfaces of a mold and assumes its shape. Watch this video [1:28] to see this ancient process (footage courtesy of Mark Taylor and David Hill-the Roman Glassmakers). Created by Getty Museum.