Glass fusing is the process of using a kiln to join together pieces of glass. If you apply heat to glass, it will soften. If you continue to apply heat, the glass will become more fluid and flow together. Two or more pieces of glass can stick (be "fused") to each other. The glass used in these processes must have the same rate
of expansion and shrinkage.
Many people also use the word "fusing" to include bending and shaping glass using the heat of a kiln. Inclusions can be placed between the layers of glass. The manipulation of the glass can take many forms, but the most common is slumping, where a mold is used to cause flat or already fused glass to take on the shape of a bowl, a plate, or similar object.
In recent years "kiln-forming" and "warm glass", have both become terms to describe both of these process.
