I just made a 8x10 pinhole camera out of foamcore last night because I was bored. Since I found out you can contact print with paper, I figured I would buy some 8x10 paper since it's pretty cheap, because I don't know but I figure 8x10 film is expensive. I found pinhole exposure calculators online at mrpinhole.com but they depend on the ISO of the film you use. But the paper I was going to buy (Illford multigrade IV from amazon.com) doesn't have an ISO rating. It seems like it would make sense that it would. Anyway, is that a decent paper? I heard that I could buy laser-cut pinholes online, is that true? How important in a pinhole camera is it that the paper be held perfectly flat? Since focus shouldn't be an issue I figure it should be pretty forgiving.