A corrugated board is secured to the inner wall of a cavity wall construction to establish a defined spacing between the inner and outer walls and prevent excess mortar from bridging to the inner wall. An assembly can include a body and a member that is made from a different material that the material from which the body is made. A central processor communicates with a speaker interface circuit by means of a data bus. This enables forming of successive recesses and projections on the thin metal plate, while reducing ductile cracks and warpage. One embodiment comprises arranging at least one metal shape to define boundaries of a casting dam, lining the boundaries with ceramic fiber paper to create a containment including the at least one metal shape and the ceramic fiber paper, inserting glass in the containment, and firing the glass and the containment in a kiln to cast a glass shape corresponding to a portion of the containment.