Pressed glass
Pressed glass is made by placing a gather of hot glass in a metal mould and forcing it into shape with a metal plunger. The mould defines the exterior while the plunger shapes the interior. The process allows relief patterns to be repeated efficiently.
Features
Pressed glass may show mould seams, repeated patterns and an interior defined by the plunger. Finishing may reduce the seams. Mechanical glass pressing developed in the United States during the 1820s and 1830s, but this does not date every individual object.
Confusions
Mould blown glass is inflated against a mould and lacks a separately plunger shaped interior. Cut glass is decorated by removing material after forming. Examine seams, edges, base, weight and finishing traces before assigning the technique.
