Hi, I decided to put my two cents into this one. I have an MA in Archaeology and my Master's Thesis was on a form of rock art called petroglyphs. Petroglyphs are pictures etched into stone by chipping away the outer, darker surface of patina to get to the lighter rock underneath. I also recorded a cemetery as an archaeologist, as part of a site survey for an environmental report. It was a cemetery attached to one of the California missions. Those photographs came out great. Compared to the petroglyphs, it was a piece of cake. Dealing with recording rock art is exactly the same as dealing with recording tombstones, in my opinion. It has been a lot of years since I worked in archaeology, and even more since I photographed petroglyphs. But, I will try to remember what I learned about it. I can tell you that the photography suggestions on the list were really great, in my opinion. Black and white film, the most contrast you can get, etc. was right on, with the minor exception that sunlight is any kind of help. It isn't, since it cannot be controlled. Since petroglyphs were usually carved into patinated stones, the lighter inner surface stood out when they were first done. Gradually, however, patina once again would cover the drawing. Then, the contrast is no longer there, making it very difficult to see or photograph. Not that I could afford any special equipment as a graduate student, but I read at the time that using a polarizing filter on the camera might have helped. I remember we tried to photograph the glyphs during the afternoon, when the shadows were longer. When that didn't help, I would put up a shade to keep the sunlight off the stone while photographing it (sometimes lining people up to block out the sun). Then I would try reflecting light onto the drawing, or shoot from an angle to get some contrast. I took a lot of pictures of the same picture from different angles, and always ended up with something I could use. Though a polaroid camera does not use black and white film, it can come in handy, because it can give the photographer some sort of idea how the other pictures will come out. As to cleaning the stones. The most I would ever use was canned air (like photographers use to clean their lenses) to dust the drawings off. As an archaeologist, I would never chalk a drawing. I would never even use water on them, why should I help the erosion process? Rubbings, in my opinion, are just as damaging as chalking, washing, etc. unless the stone is very stable and the rubbing is done very lightly. As I said, just my two cents. Recently, in Denmark, I tried to photograph my ancestors' headstones, and wasn't very successful. My excuse is that it had been a lot of years since doing anything like that. Also, I wasn't used to dealing with the reflection from snow on the ground and didn't have black and white film with me, either. I do have a good excuse for not being prepared. I had expected to find only official records of my ancestors in Denmark, if that. But, not only did I find plenty of records, a distant relative who had already done work on my direct line and showed me where they had lived and died, and second cousins who also showed me where the bodies were buried. =/:-) Carole