This came about, because I have a limited amount of woodworking gear. These mediums are taller, and because they are, there is no need for a traditional bottom board. For one box you'll need 1 pc. 1x8x6. Cut sides at 19 7/8, cut front and back at 14 3/4. I don't have a table saw, so I use handheld dovetail saw and chisel for making the rabbets. Glue and nail (or screw) front and back pieces between the 2 side pieces. Top with a migratory cover. As is, this medium is 1/8" shorter than a medium sitting on a standard bottom board.