A printmaking technique in which colour is applied to a printing surface covered with different materials and texture, then transferred onto a substrate such as paper or fabric. It combines the intaglio and relief methods of printing. The surface may be made of a flexible material, such as cardboard, or a harder material, such as wood. The materials are applied to the surface using an adhesive. It derives its name from the Greek collo (glue) and graphos (to write or draw).