How to Identify Pressed Glass

In looking at different kinds of glassware, pressed glass appears as a specific kind of process that was done in certain time periods. The making of pressed glass proceeded from early "blowing" glass procedures, and later was eclipsed by the popularity of "crystal" in the early 1900s. The majority of pressed glass was made around the 1880s, when the technology was fairly new. Knowing about aspects of pressed glass will help you date antiques and assess value.

Difficulty: Moderate

Instructions

1. Look for a small bulge or mark near the stem of the piece. A blown glass piece will have this "rod mark" from where the glass piece was separated from the blowing rod. A piece of pressed glass will not have this mark.

2. Look for imperfections that are consistent with the glass-blowing process such as bubbles or shifts. Pressed glass will not have these features, as pressed glass pieces are not blown but carefully shaped by a mold.

3. Because pressed glass is made in a mold, look for seams along the sides of the piece to identify it as pressed glass. The piece may have three or four seams along its edges, slight marks where plates were unevenly pressed together.

4. To differentiate pressed glass from crystal, assess the weight of the piece. Crystal, as a product made with lead, will be heavier than pressed glass.

5. Look for manufacturer's marks. These telltale signs, usually added to molds by manufacturers, can tell a lot about a glass piece, such as the period or maker, and can help identify a piece as pressed glass.

Resources

• Brief history of pressed glass
• Glass types