I did a little experimenting tonight with Lumen Printing as an example for my photography class tomorrow. The process takes advantage of the fact that photo paper darkens when exposed to light outside of the darkroom. A sheet of paper is covered with a negative and then light is pointed at it. Usually the sun would be the light source, but it is dark so I used a halogen shop light (the same one I use for burning silk screens.) After exposure, the paper darkens and an image appears. There is no need to develop in any chemicals. The paper is supposed to be fixed in a very week fixer solution to keep it from darkening further and eventually disappearing. I don't have any fixer around, so I just scanned the image to save it digitally. If the image lasts till tomorrow, I'll try fixing it properly.