Textured Glass Slumping

No one knows exactly when the technique of fusing glass began but there is evidence that the Egyptians knew how to fuse glass as early as 2000 BC. Some argue that the Romans were better and more prolific glassworkers. During this period, bowls and plates were produced by forming a glass sheet over a mold or form. For about 2,000 years, fusing was the most widely used method for making small glass objects.

By the third century AD, warm glass fell out of favor, eclipsed by a new hot blown glass technique. It was not until the emergence of the European Arts and Crafts movement, in the late 19th century, that warm glass was revalued as a decorative art form. Today, contemporary artisans have rediscovered these ancient techniques. The popularity of warm glass is being fueled by current trends in design and by the ease of modern kilns. Fused glass techniques are generally used to create beads, glass tiles, or art glass pieces.  

          In this project, a clay texture mat was carved into the student’s own design, bisque fired in the kiln, and then used as a mold to slump glass into. We used raku clay that was cut into 3x6" rectangles, about 1" think. Students used various clay tools to carve out their recessed designs. They were careful to avoid undercuts that the glass could potentially flow into and get stuck in: 

The pieces in the kiln ready to be bisque fired

Two coats of kiln wash were applied to the fired tiles. Then, clear glass sheets were placed on top (using clear glass as a base allows the texture to be seen more clearly) and colored glass mosaic chunks and stringers were added to accentuate the design and create interest. Here are the kids working on this step:

The pieces in the kiln ready to be fused/slumped

The molds and stacks of glass were placed in the kiln and then heated through a series of “ramps” (rapid heating cycles) and“soaks” (holding the temperature at a specific point) until the individual pieces began bond/fuse together and “slump” down into the textured mold. The pieces then need to cool slowly, a process called “annealing” to prevent the glass from breaking.

Here are some of the final works on display. They were really hard to photograph and most appear flat in the pictures, which they are not! This one is of a lizard- the easiest part to see in this photo is the curled up tail on the left, but the whole thing is raised and the details like the eyes are very cool!