I prewashed 4 panels of fairy flowers that had about 15 fairies per panel...I'll never prewash panels again. Each was wonky. I added borders and squared up each before adding to the quilt. It showed, but my 6-year-old granddaughter doesn't notice it and was thrilled with the quilt. With a larger center panel adding borders and squaring up shouldn't be quite as noticable as with smaller squares, unless it is way, way wonky.