William Willis (inventor)
William Willis Jr. (1841–1923) is a British inventor who developed the platinum printing process, an early form of photography, based on the light sensitivity of platinum salts, originally discovered by John Herschel.
Willis made the first platinum print in 1873 and patented it, but the process was imperfect, attracting little interest. In 1874, the British Journal of Photography announced his Platinum Printing process. It gave a report of the process on 4 June 1875. By 1879 he had improved the process sufficiently to justify founding the Platinotype Company to market his papers.
He began marketing his pre-coated papers in 1880. Taking his cue from Daguerre's marketing practices with his Daguerreotypes, Willis sold licenses to photographers wanting to use his process, and then sold them the materials.