Originally Posted by
mucky
You always sew with a relaxed bottom so if you have more fullness in the quilt side sew in the border side and if more fullness in the border sew on the quilt side. One exception is if your border is on straight grain sew on the border side.
Any fullness eased in on the border guarantees they'll be wavy. "Easing" is basically a slight gather. Even slight gathering on the quilt side will guarantee tucks and fullness and mess on the binding side.