If you use POP or another alternative process, you can contact print with the sun, like AndyK says. In general, these processes require substantially denser negs than you would use for enlarging paper, and somewhat denser than you would use for Azo. Here are three negs in printing frames being exposed to the sun for albumen printing--

http://www.apug.org/forums/attachmen...achmentid=5113

I find the negs that print best in albumen take about an hour to expose in shade, and about 15-20 minutes in direct sun.