Abstract: A system of prefabricated plaster relief forms are manufactured to be applied to prepared walls of a building, such as a home or other structure. The prefabricated forms are made of an open work lattice material formed into a channel shape having a top, two depending sides and outward directed flange portions. The lattice material is configured to receive and hold a cementitious material such as plaster. The top and the sides of the prefabricated forms are configured to present a protuberant contour projecting away from the flange sections and thereby outwardly from the prepared wall. The cross section and the ends of the prefabricated forms are shaped to align end-to-end with identically shaped forms. Alignment of a plurality of such forms in a longitudinal direction provides a continuous relief band along the wall of a structure. The prefabricated relief form flange sections are configured for attaching to the prepared walls by means of nails, screws or adhesive.