Hello I am fascinated about the idea of a photograph being an temporary object. Now I want to make a dissappearing photograph. The idea is that there will be a (b&w or color) photograph in an (lightproof) envelop, the reciever of this envelop will take the photograph out and, it being exposed by daylight, will go black before his/hers eyes. Question, is this possible? I did tests with developing bariet and platsic coded photopapers and did wash them but without fixing them I dried them and put them in an envelop, when I opened the envelops in daylight, I was surprised to see that they would only very slowly change color after being exposed to the light. Does anyone now how to fasten this process? Ideally it should turn black in a minute or so! Thanks a lot!