May 28, 2013
pleasekillmenowforiamworthless asked: Did you build your own UV exposure box? I am planning on doing some gum printing at home and your setup looks quite reasonable. Do you know where I can get schematics for building one?
I don’t have schematics for building an exposure unit but I built my exposure unit box by using white Melamine shelves from Home Depot: http://www.homedepot.com/buy/3-4-in-x-15-3-4-in-x-97-in-white-melamine-shelf-1605490.html and four two Strip Fluorescent fixtures 24 inches from Home Depot:http://www.homedepot.com/p/Progress-Lighting-2-Light-24-in-White-Fluorescent-Strip-P7266-30EB/202599765#.UaTmkpVSXZQI use eight Sylvania 20 W 24-inch bulbs (F20T12/350BL/ECO) about 3 inches away from the print. I ordered the bulbs from http://www.buylighting.com



I also made an exposure unit for my students at Queens College where I built the box using 2×4 lumber and a plywood top and stapled black cloth on the sides with enough room underneath to be able to place a contact printing frame and make test strips.
Of several kinds of UV lamps such as BL (which you use), BLB, and GL. Which is best suited for making gum bichromate prints?
I have only ever used the BL bulbs for my exposure unit. I’m not familiar with the GL bulbs but the BLB bulbs are the dark purple bulbs–which were typically suited for use with black light posters from the 70’s 🙂 They could work but since they’re not at bright the exposures would be much longer. I’ve had consistent results with the regular BL bulbs. Hope this helps.