[URL]http://www.substance.com/photos-artist-exposes-drugs-visual-essence/9029/[/URL] Read this article today and got really interested in doing this myself using coffee or caffeine. The article says that she dropped the substance on pre-exposed film. What does this mean and how do I achieve this? Pre-exposing the film that is. Thanks alot for answers! Will post results if I got some help. Cheers