Treated down (“dry down”) is a technology that was developed to decrease drying time for hotel comforters in commercial dryers, and we very purposefully do not use it in any of our products. Besides decreasing the longevity of the high-quality down we use by stripping the down of its natural oils, we’ve also seen little real-world benefit to the use of durable water repellency (DWR) directly on the down plume. Wet down clusters do not insulate, regardless of any coating applied to keep them dry, and we’ve found that body heat or ambient air flow -- rather than a dryer-- isn’t sufficient to make dry down an effective tool in keeping you dry, and therefore warm. Treated down is also more prone to clumping than untreated down, which makes it tricky to keep properly lofted within a garment or sleeping bag. The bottom line: untreated down will last longer and perform better than treated down, a view shared by some of the field’s leading manufacturers. Because of this, it’s important to keep your down sleeping bags and garments as dry as possible, which is why all of our sleeping bags and garments use a water-repellent or waterproof fabric.