Friday's class at Glass Expo was Cast Away with Lisa Vogt. Cast glass is made by fusing a thick pile of glass (usually chunks, but also frit, strips, etc.) into a thick solid piece of glass. The chunks have to be contained in some manner in the kiln so that they don't flow out into a mess in the kiln. In the photo below you can see a square piece which is contained by walls of 1/8" fiber paper, a fibrous material which will not burn.
The final tile (photo below) is embossed on the bottom by another layer of fiber paper cut into a design of intersecting arches. I used aqua and turquoise frit to add color. The final piece is about 4" square and 3/4" thick.
The design for the next piece was made by carving into a 3.5 x 3.5" chunk of Kaiser Lee board, another non-flammable material that carves like smooth styrofoam. The design was made with purple and yellow frit and lots of clear glass chunks. The top photo shows it ready for firing and the bottom shows the final piece (still in need of cleaning).
The final casting I made included turqoise strips of glass and red frit in a round mold of fiber paper. I don't have a pre-firing picture; the photo below shows the piece from the top and from the side. It is about 6" in diameter and 3/4" thick.
I'm not sure how much casting I'll do in the future, but it'll be interesting to play with further. More glass is better, right?
