The glass casting process involves the creation and use of plaster-based molds. Using plaster-based molds for glass casting is an art.
A variety of processes can be used to accomplish this feat; however, the two most common methods for making plaster-based molds are open-faced molding and lost wax casting.
In both methods, the mold itself is used only once. A plaster-based mold material is mixed with the appropriate percentage of water to create a slurry. This slurry is then poured around the pattern and allowed to set or harden.
After proper curing, the pattern is removed by pulling it from the mold; by steam removal, or by heat removal. After the pattern is removed, the glass can be placed in the mold.
The method of glass placement varies from artist to artist, based on preference and experience.