The backing is leftover blocks, just as the front had been. The middle diamond came from my recent baby quilt. The kite squares were rejects from Bouncing Boxes. I didn't have enough of the dark grey to make the background, so I dug around for my unloved fabric. Light colors didn't work, but oddly enough this red did. None of the other reds. Not even a dark green. How odd.
It's loud - more than the front. But since it's the backing I'm not too concerned with the volume.
I sandwiched it with batting from an old comforter my sister gave me. The project is a lot of recycling and upcycling! Initially I folded the batting into three layers for some padding for my knees. However, it was hard to pin and I feared it would be simply too puffy. I removed a layer, which pinned together easier. I'll start quilting as soon as I straighten out my sewing machines. I plan to quilt this heavily since it's supposed to be mostly flat. We'll see what inspires me.
I had hoped to have it quilted by Halloween but got sidetracked with sewing machines!
Once it's quilted I'll attach the rubber shelf lining (in a way yet to be determined).