Looking at the pile of fabric I had left, and no desire to make another quilt with it, I decided to piece the backing. Originally it was to be 36 squares 16.6" each, but that got modified. The outer border (not shown) is rectangles, to make it 4" bigger all around. The pile of leftover fabric is now very small.
Decided to quilt it myself, the design shown will be on all 16 squares, still deciding on the sashing and border quilting.