Stained and Mosaic These are some of the oldest ways of working with glass. The glass is never heated during the entire process. In our stained glass classes, you will cut and grind pieces of sheet glass to fit inside a pattern. Then you learn the process of foiling and then soldering glass together with lead solder. In mosaic classes, you will arrange small fragments of sheet glass on a tile, and then apply grout over top and in between to keep all the pieces in place. This class has the most artistic freedom of the first experience classes.