I often piece my backs with the left over from the front. My favorite LAQ has never complained. I iron my seams open and cut off the selvage edges. A friend of mine decided to do the same when she saw mine. LAQer fussed at her so I asked why she didn’t fuss at me...ir was because the back wasn’t pressed and selveges were not removed. I never thought it would be a problem and had never thought to ask.