Most of that volume is air, and I use vacuum bags for storage/laundry organization. My jackets only take up the volume of a few t-shirts en route. Sweaters are

Most of that volume is air, and I use vacuum bags for storage/laundry organization. My jackets only take up the volume of a few t-shirts en route. Sweaters are more difficult, because I don't want to put handknit fabric into a vacuum bag, so the times I've needed to travel with those I wear them onto the plane as normal clothing, or slung over an arm.