In glasswork, what is slumping?

• A. Casting
• B. Slumping
• C. Fusing
• D. Cold-working

Answer: (B)

Slumping is the process where glass is heated until it becomes soft enough to sag or fold into the shape of a mold, forming a curved, bowl-like or dish-like piece as it cools. This is typically done in a kiln at a temperature that lets the glass flow gradually without fully melting into a pool, so it can take the mold’s contour. It differs from casting, which pours molten glass into a mold, from fusing, which focuses on joining pieces together or bonding surfaces (often without a significant change in shape), and from cold-working, which shapes glass at room temperature using tools. Slumping is all about the glass yielding to gravity and the mold to become a new molded form.