. Hello everyone. I'm looking for something photosensitive which is mildly acidic, but then can be safely fixed. I want to experiment with some crude etching ideas - coat various soft substances with something that turns acidic once exposed to light and then, under the image, watch the light-exposed areas of coating eat into the surface. So 2 problems really. 1 How to get a substance that is photosensitive and turns into a mild acid on exposure to light, and 2 How to stop the corrosive action with a fixer. Any ideas most welcome! Thanks... Mark http://www.otherlanguages.org .