Now questioning my direction with exposure systems. I was going to use a bank of 9-12 spiral BLB bulbs. Then I read Vaughn's statement that that BLB causes a soft print because of the thickness of the tissue. I plan to make my tissue in the way other folks have with a magnetic frame. The magnetic stock I have to use is 2mm thick so that will be the final thickness of the tissue. In my mind this is thick, and I can see the reasoning behind Vaughn's statement. I want sharp prints and it looks like a BLB box is out. No problem. When I printed centennial POP I used my hydroponics lights. I have a multi spectrum grow light that worked well and I also have a metal halide bulb that worked. Unfortunately these are both 1000 watts. (it was a big indoor garden) Would there be an issue using these or will the heat generated melt the gelatin? Can I use a smaller watt bulb with the 1000 watt ballast?