Somewhere on YouTube there is a video that shows the background square folded into quarters, ironed, then unfolded, four points folded into center, ironed,and zigzagged down,the raw edges of that zigzag is covered by the colored square in the construction, the back of quilt shows the zigzag on the smooth side of fabric..anyway have one that I started that way...a UFO, at this point, but it went well as I worked it. The back is finished, no need for backing, batting....and I turned those background bias slivers over, and sewed by machine....perfect meeting points!