A process for making relief plates by using acid to etch away the non-printing areas of a photographically produced image. The subject is photographed through a wire or glass screen, which breaks the light in a way that sensitizes the metal plate in a dotted pattern. Darker areas are created with larger dots while highlights are rendered with finer dots. When printed, the finest screens create the most precise detail. This process was used principally for reproducing illustrations in the earlier part of the 20th century.