Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is grained (adding a pattern to the plate) and then coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio plate that can reproduce detailed continuous tones of a photograph.  Because of its high quality and richness, photogravure was used for both original fine art prints and for photo-reproduction of works from other media such as paintings.  In France the correct term for photogravure is héliogravure, while the French term photogravure refers to any photo-based etching technique.