General

A relatively low-quality brick used behind face brick or other masonry.

A thin coating (such as sprayed neoprene) on the back side of a fabric to increase its durability, its resistance

On the theater stage, a large, taut, flat canvas, usually hung from the grid at the rear of the stage

An asphalt-coated water-repellent strip which is applied behind the joint where the vertical edges of two shingles meet.