Viennese slide
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In 1909, Rudolf Schneider from the police identification office developed the first film for taking and fixing fingerprint traces, which is still produced today under Viennese film - meanwhile by his great-grandson.
history
In 1902, dactyloscopy according to the Francis Galton - Edward R. Henry system was also introduced in Austria . A problem with dactyloscopy at that time was the exact securing and removal of fingerprints at crime scenes. A police agent from the Vienna Police Department was doing pioneering work in this area: Rudolf Schneider. He thought about ways to better secure fingerprint traces. In 1909 he developed a "film for removing and fixing fingerprint marks". The trace of the impression was lightly dusted and the dark, slightly adhesive film was pressed over it. The film was carefully peeled off and the light papillary lines of the trace cause drawn on it were photographed and enlarged in the laboratory. Schneider patented the process in 1911.
His technique was based on the fact that the footprint was made visible by dusting it as before and then lifted off the object on which the trail was located by means of a film. The film provided with the imprint is then peeled off and can now be photographed at any later point in time.