Collotype print, Foto reproductie Das Colloseum in Rom 1897 Seemann's wandbilder no. 71 Collotype print by C.G. Roeder, Leipzig Collotype is a gelatin-based photographic printing process invented by Alphonse Poitevin in 1855 to print images in a wide variety of tones without the need for halftone screens. The majority of collotypes were produced between the 1870s and 1920s. It was the first form of photolithography. A reproductive printmaking technique that is photographically based. Although collotype is increasingly rare, in the early 20th century it was employed for its effectiveness in reproducing the subtle delicacy of drawings and photographs. A photographic negative is projected onto a printing plate coated with light-sensitive gelatin that hardens and becomes receptive to the application of ink. Paper is laid on top and the image is printed on a press