How can I know how long to expose it for contact printing? Last night I did a test strip of the paper, to see how much exposure I got by briefly flashing the bathroom lights, then moving the covering a bit and flashing again. So the strip goes from 9 flashes on one end to no flashes on the other. It turns out 1 flash is dark grey and 2 flashes is fully black. I suppose I can use the white, dark grey, and black sections from the test strip to do a test-contact print on more strips of paper. I will use my enlarger for it this time, but do you suggest a ballpark exposure for the test-strip contact print? I will probably start at f/8, 30 sec, but I have to wait till it gets dark anyway because the bathroom door leaks a lot.