Photogravure

Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio print that can reproduce the detail and continuous tones of a photograph.

The earliest forms of photogravure were developed by two original pioneers of photography itself, first Nicéphore Niépce in France in the 1820s, and later Henry Fox Talbot in England. Niépce was seeking a means to create photographic images on plates that could then be etched and used to make prints on paper with a traditional printing press. Niépce's early images were among the first photographs, pre-dating daguerreotypes and the later wet collodion photographic process. Talbot, inventor of the calotype paper negative process, wanted to make paper prints that would not fade. He worked on his photomechanical process in the 1850s and patented it in 1852 ('photographic engraving') and 1858 ('photoglyphic engraving').

Photogravure in its mature form was developed in 1878 by Czech painter Karel Klíč, who built on Talbot's research. This process, the one still in use today, is called the Talbot-Klič process.

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. Photogravure is distinguished from rotogravure in that photogravure uses a flat copper plate etched rather deeply and printed by hand, while in rotogravure, as the name implies, a rotary cylinder is only lightly etched, and it is a factory printing process for newspapers, magazines, and packaging. In France the correct term for photogravure is héliogravure, while the French term photogravure refers to any photo-based etching technique.

...
Wikipedia