The term for a down sleeping bags ability to expand and fill out the baffles. New, clean down lofts (expands) much faster than a well loved bag. Storing a down bag uncompressed is the best way to preserve its ability to loft quickly. All of our AlpineDream sleeping bags are shipped with a large cotton stuff sack to store your bag when it’s not in use. We also ship and store Alpkit sleeping bags uncompressed.