I built these and they held old pressed steel to trucks from the 50s all the way around my office. The backbone is 2x4 milled down to 1 1/8" x 2 1/2". Holes counter sunk into the backbone every 16 inches to screw to wall studs. The black shelving then slides onto the backbone and is tacked on. I used an air stapler an tacked on every 6 inches or so. Another milled down board the sets in the front face of the shelf and was secured in. Did not have to be stapled as much as the backbone. To finish it off I used the 1 5/8" piece of trim board. Flush with the bottom of the shelf and with an approximate 1/4" lip to keep anything from rolling or vibrating off. They were beautiful when up and I received many compliments on them. My office was something like 10x12 ft. I also have many unfinished pieces (that were not painted) if you wanted to do more. Each piece taken down and numbered. Includes all the lag bolts, washers, and tapcons I used. If your look g for something like this, here is your chance to save a bunch of time and money. You will not be disappointed in the finished product. $50.00 first everything.