If you hang, make sure the other clothes in the closet aren't shoved against the sleeping bags. I store mine in the big cotton storage bags that came with them, on a closet shelf, with nothing on top and no crowding. And make sure that whatever you cover them with is breathable. You can just safety-pin an old sheet around the hanging sleeping bag; no need to sew anything fancy. Some people store their sleeping bags under the bed, but be sure to wrap them gently in a sheet to avoid their getting dusty.