Early photolighographic test by the inventor of the process.

Alphonse Poitevin (1819-1882) was a chemical engineer who spent 35 years experimenting with photographic chemistry and photomechanical printing. A pioneer of photography’s earliest days, his first images were created with the techniques of his immediate predecessors: daguerreotypes, paper negatives and salted paper prints. However, as a chemist, he was also an inquisitive inventor eager to discover new photographic and photomechanical methods. Today, Poitevin is remembered most for establishing the fundamental principles of four non-silver process families: photolithography, collotype, dichromate relief system, and the carbon pigment process. His inventions refined existing techniques and made the mechanical reproduction of images and thus, the illustration of printed books, possible.

Poitevin was the first to coat a lithographic stone with an albumen layer that had been rendered light-sensitive with dichromate salts. (1856 – 1857) Following exposure to a negative, the entire surface was coated in printer’s ink, then washed in water, with the effect that the unexposed, and therefore un-hardened areas would absorb water and cause the greasy ink to detach, whereas the ink remained attached to the surface in the exposed, hardened areas. After drying, the stone could be used for producing multiple lithographic prints in the usual manner.

With his photolithographic technique of 1855, Poitevin won the much sought after Grand Prix du Duc de Luynes in 1867, a contest run by the Societé française de photographie. He also won a number of prizes for his non-silver photographic techniques, including a gold medal at the International Exposition in Paris in 1878. He held five patents, and his book Traité des impressions photographiques was published twice: the first edition in 1862 and a posthumous second edition in 1883. He published over 80 technical articles in professional journals of photography and printing. Poitevin died on March 4, 1882, in the village of his birth. [1]