I have previously posted on here about the oil can display at the Pontiac Museum in Pontiac, IL. I love the room full of cans. Examining a blow-up of the picture I took there, I decided they probably made their racks with 1x4 lumber, butt joints, no backs, and allowed the cans to protrude from the shelves about .5 inch. I think the look is great for the large volume of cans they have, which I suspect are all empty. I only have a few cans I wanted to display and some of them are full, so I modified their idea for my use. I purchased 1x6 lumber and cut 2 pieces to 26.75x4.25, 2 pieces to 17 1/8x4.25, and 3 pieces to 17 1/8x4.0. Each of the long pieces has a 3/8 by 3/4 rabbit on each end and 3 dados 3/8x3/4 spaced 5.75 inches apart. After assembly, I added a 1/4 inch plywood back.
Pontiac MuseumOil Can Rack