Leah Day posted a great idea recently about how she stores quilts - particularly wall hangings. She takes a pool noodle (long styrofoam floatie thing for in a pool). She makes a fabric sleeve to cover it. Then rolls the quilt around the noodle, right side out from top to bottom. Then she makes a second fabric sleeve to fit over the whole thing. Store flat. She also uses that for shipping quilts. The reason for rolling them right side out from top to bottom is so that they'll hang straight and the bottom won't curl away from the wall.