Several identical molds could be taken from a single patrix and then be used to mass-produce copies. In the Roman provinces, potters seem to have used imported Italian lamps as a patrix, casting molds directly on the imported original. The lack of sharp relief could also have resulted from the gradual abrasion of the mold as it was used over and over again. The discus , or central portion of the top of the lamp, typically received these decorations. The practice of molding permitted the large-scale industrial production of lamps with standardized form and decoration.
Some lamps bear a signature or pictorial design stamped on the base.