Pereira, Catarina2017-11-202017-11-202016PEREIRA, Catarina - Materials and techniques for retouching glass plate photographic negatives in the beginning of the 20th century. In 3rd International Meeting on Retouching of Cultural Heritage, RECH 3. Porto, Portugal, 23-24 October, 2015. - In BAILÃO, Ana; HENRIQUES, Frederico; BIDARRA, Ana (eds.) - RECH3: Postprints. Porto: Escola Artística e Profissional Árvore, 2016. p. 65-72http://hdl.handle.net/10400.14/23495Retouching glass plate negatives was a practice that emerged about the same time as the glass plate negative itself. How was photography being retouched in the early 20th century? Today there are generally available known digital tools. A hundred years ago, the retouching was done by hand, by the photographer, or by specific professionals that don’t distance themselves, in technical demand, of the arts of drawing and painting. But the retouching was invisible in the final object, because the changes were done on the negative. Its contemporary books, in the form of manuals, are a window to the past telling us about the techniques and materials used. Existing archive collections of photographic glass plate negatives are testimony to the expertise of photographers and the practical use of those books. The present work will show examples of tools and materials used for retouching of photographic glass plate negatives, taking as an example a portrait collection at the Photographic Archive of Lisbon. Also some considerations are done about the conservation of retouched glass plate negatives in archive collections.engPhotographyGlass plate negativeHistorical retouching20th centuryconference object