An optic mold is an open, cone-shaped mold with a pattern on the inside. When hot glass (on the end of a mandrel or punty) is pressed into the optic mold the pattern is transferred to the glass. After removing glass from from the mold the glass is often twisted to create a spiral design.
Optic molds are available in many shapes and sizes. Small versions that are just a couple inches tall are intended for glass artists working with a torch. Bigger versions suitable for the glass blowers working with large gathers of glass are also available. Common patterns include stars that have from four to more than thirty points.
An optic mold is an open, cone-shaped mold with a pattern on the inside. When hot glass (on the end of a mandrel or punty) is pressed into the optic mold the pattern is transferred to the glass. After removing glass from from the mold the glass is often twisted to create a spiral design.