•One piece craft fuse (aka iron-on craft interfacing) 20.5" x 1.5"
•One piece heavy stabilizer (aka heavy weight sew-in interfacing) 20.5" x 1.5"
•One piece thickish, stiffish material 20.5" x 1.5". I used natural canvas/ duckcloth. I included this because I really, really need my straps to not feel like flimsy ribbon. But that's just me - you can leave this out if you like.
•Some vinyl. I used upholstery-grade vinyl that was black on both sides.
•Two 3/8" dog collars. The thing in the picture is a dog harness, which was a costlier alternative. I found the cheaper-and-just-as-good Target dog collars later.