Joseph-Rose LEMERCIER was one of the most important Parisian printer-lithographers of the 19th century. He worked for the greatest publishers and artists of his time. He played an important role in the diffusion and the generalization of the photolithography process which made it possible to transfer a photographic image to a lithographic stone and to achieve thanks to this printing with printing ink of this image. Of modest origin, son of a Parisian basket maker, he was born in Paris on July 6, 1803. He apprenticed with Édouard KNECHT, nephew and successor to Aloys SENEFELDER, the inventor of lithography. He started his own business in 1828; in 1831, he moved to 57, rue de Seine, in an old tennis court. Between 1852 and 1855, he associated with the optician Lerebours, the chemist BARRESWIL and the chemist and photographer Alphonse DAVANNE to develop such a process, but the result - of too long and complex implementation - was not industrially exploitable. In 1855, Alphonse POITEVIN invented and patented a process that could be implemented industrially. POITEVIN first seeks to exploit his patent himself and opens a workshop in Paris. But, from October 1857, he sold his patent and his workshop to LEMERCIER. Lemercier works for all the major French publishers of his time. He is the printer of artists such as Odilon REDON, Édouard MANET and Alphonse MUCHA. Joseph-Rose LEMERCIER was made a knight of the Legion of Honor in 1847, then was promoted to officer in 1878. His nephew, Alfred LEMERCIER, succeeded him when he died and ran the company until his own death in 1901.