The History of Slumping

As glass designers we spend a lot of our time slumping. You heard me right we love to slump. Slumping is the term that is used to describe how we form warm glass into a shape that our customers will want for their backsplashes, wall or stand alone pieces of art, countertops or glass boards. By applying heat to the point where the glass will soften, our glass designers increase the fluidity of the glass causing the glass to 'slump' into or onto the mold underneath. Here's how we do it. Once the oven reaches the right temperature we put a sheet of glass in, 'slumping' it over a form or into a mold. We use molds that are made of plaster, clay coated with plaster, graphite, sand or steel. Once the glass is formed, we reduce the temperature so that it can cool off or anneal. Slumping has been around since the days of the the Romans. They used slumping on everything from vessels to bowls and plates. They would place a sheet of glass over a mold which produced vessels with rough surfaces, which could then be ground or polished to a smooth finish. Some of the other techniques that they used to get their unique pillar-molded bowls was through the use of a special slotted tool to for the glass into a ribbed shape before it would go to slumping. This helped create a ribbed effect on the exterior of the bowl. Glass is a malleable material that can be made into almost any shape that you want. In my coming posts I'll write about them to give you a better idea of the techniques that we use.