Sea to Summit's Compression Sacks will help you squish down your gear with a 2:1 mechanical advantage. They're designed to evenly distribute the strain of maximum compression, unlike many compression sacks which will fall apart when stressed.
210 Denier Base & Sides
Sewn on Cap Construction to Prevent Tangles
5 Sizes to Compress All Your Gear
Should not be used for long term compressed storage of down/dacron/fleece items.