Glass-on-Glass Mosaics can be various sizes and have more detail than a stained glass piece. If sealed and protected for the outdoors, they are beautiful when used in fencing or to add privacy to a front porch and seating area. I enjoy abstract patterns and letting the glass flow, but they can also be made into a specific pattern. Pieces are attached to the backing glass and then grouted and sealed three times. A final coat of wax is the finishing touch.