If you have a glat surface, such as an unused bed, have you tried just laying it flat on the bed and walking away for a few days? I sometimes just lay my quilt tops, batting, and backing over my 12 foot frame for a few days and somehow, a lot of times any creases or fold lines just disappear. I do have my long arm in the basement and live in a humid state at times but it even works in the winter most of the time.