Loose packing soft bulky items like clothing and sleeping bags is a great way to shave weight from your pack and make better use of pack volume. When items like clothing or sleeping bags are packed inside a stuff sack they become tightly packed rigid objects. When you then pack all these rigid items inside your pack you get voids in between. This wastes space in your pack and adds weight. I once took a whole pound of stuff sacks out of a customers pack. Next time you pack your pack try stuffing your sleeping bag loose into the bottom of the pack. Squish it down as tight as you can and then pack your other heavier items like food and cook gear on top. Use your clothes to fill the space around the heavier items. You will find that yoou end up with more useable space inside your pack and that your pack is lighter. Win, Win!