Great for stuffing winter clothes
I bought a bunch of these to pack my munchkins' (2 & 3 yrs) winter clothes for a 2-week Christmas trip, and love them. I managed to stuff 3 pairs of ski pants into a size 4 sack, and ski jumpsuits each fit into a size 3. I wonder why I hadn't bought them before. They are also great for organizing small items like hair ornaments and toys.
They compress bulky clothes so well that we managed to pack everything into our bags without exceeding airlines' allowances. I have never been able to pack so much gear into so few bags. I highly recommend them.