The Super Down Sleeping Bag has arrived and orders are shipping. For those of you that backpack hunt, your sleeping bag contributes more to the weight of your pack than any other item. There have been recent advancements in sleeping bag design, construction, and fabrics that allow sleeping bags to cover a wider range of temperatures and conditions. Below is some information that I found useful in my sleeping bag development research that I want to share.
EN 13537 Test
At KUIU, we use the International Down and Feather Laboratory based in Salt Lake City for all sleeping bag and feather testing and certifications. This certification of temperature rating guarantees our customer the performance and quality that we claim from our bags. Our Super Down Sleeping Bag ships out with two certificates, one guaranteeing the temperature rating with the other guaranteeing the fill power and down to feather ratio.
We do not recommend buying a bag that is not certified. Without a testing certificate the bag’s temperature rating is an opinion and there is no guarantee that it will meet your expectations.
Founded in 1961, The Committee for European Standards developed tests in various business sectors to build a strong market for goods and services. One of these tests, EN 13537, was designed to create a standard to temperature rate sleeping bags in Europe. While this test is not required by United States manufacturers, it has now become a standard worldwide. This test ensures an accurate temperature rating for your bag.
Sleeping Bag Fill
The fill of your sleeping bag drives the weight and bulk of your bag. There are three types of fill: 1. water-repellent down, 2. down, and 3. synthetic.
1. Water- Repellent Down
Water-repellent down is the most recent development in insulation. This highly specialized down has all the benefits of synthetic insulation and traditional down combined. Water-repellent down coated on an individual fiber level is the best long-term fill option available. Treated down holds its loft when wet without altering compressibility and durability features. The best water-repellent downs keep their original loftiness after washing.
The quality of water repellent down varies. After long exposures to water, most repellency starts to fail. TORAY Quixdown ™ has been scientifically proven to perform better than other treated down. Because of the durability and longevity of TORAY Quixdown ™ it is the only water repellent down I feel confident using. All of KUIU’s Super Down Sleeping Bags and Jackets are made with TORAY Quixdown.™
Down is the next to skin plume feather of a duck or goose, and older birds that come from colder climates produce the largest and warmest plumes. When compared to duck down, goose down is significantly lighter and warmer than synthetic insulation, but is expensive due to the limited supply and high demand.
The best down plumes come from Eastern Europe, specifically Poland, because birds that are typically used for harvest are 2 years older than anywhere else in the world. Most manufactures will not advertise the origin of the down because they buy it on the open market. Commodity sold down comes from Asian countries such as China, and costs less due to the larger supply chain. Asia does not produce the same quality down because it is harvested in a warmer climate and at a younger age. You should always research the down fill before buying a bag. If this information is hard to find, you are likely purchasing a bag with Asian sourced down.
Fill power is the most frequently used measure of down quality. A higher fill power reflects higher quality down because it translates to more loft per weight. I recommend the highest fill power you can afford. The demand for down has increased over the past few years and the supply has decreased, driving up the price for down by as much a 60% to 70% depending on the origin. Besides being significantly more expensive than synthetic fill, when wet, down loses all of its insulating properties and takes an incredibly long time to dry and regain loft. This is why before water repellent down was introduced, synthetic insulated bags were the only logical choice for wet hunting conditions.
Synthetic fibers used to be the only option for wet conditions. This insulation choice retains loft when wet, dries relatively quickly, and is less expensive than down. Due to their hydrophobic nature, polyester synthetic bags are an alternate choice in wet and humid conditions. If considering the synthetic route, I recommend premium synthetic insulation. Primaloft One™ or TORAY 3D Continuous Fiber™ each have very high warmth to weight ratios for synthetic insulation. However, Primaloft One™ compares to a 650 – 700 fill power down, which is a low performance in comparison to premium goose down.
Sleeping Bag Fabric
Sleeping bag fabrics also affect the durability and weight of your bag. Lower performing bags use polyester fabrics, whereas higher performing bags use nylon. Nylon is known for its lightweight durability that provides wind and abrasion resistance.
A new advancement in fabric technology is stretch, down proof nylon fabric. We use TORAY Stunner Stretch,™ which stretches without adding heavy and moisture absorbing Lycra. This allows sleeping bags to stretch with your body, significantly increasing the comfort of a mummy style bag. These fabrics are a unique breakthrough in down proof fabrics and remain incredibly lightweight and durable.
The outer fabrics of high-quality bags are treated with a durable water repellent (DWR) finish to protect your bag against moisture and condensation. DWR is a critical component in a sleeping bag because it protects your fill, especially in down bags.
Sleeping Bag Construction
There are two common baffle types: sewn through and true baffles. Sewn through baffles are created by taking the outer fabric of the bag and sewing it to the inner fabric. This compresses the down, creating cold spots around the stitch line. The most efficient way to construct a baffle is to create a true baffle. Down constructed with true baffles have several mesh walls that enclose down and prevent it from shifting.
Baffles can run vertically or horizontally. Because they are easier to construct, most bags are designed with horizontal baffles. This allows the down to shift to the outside of the baffle, creating cold spots at the top of the bag. Vertical baffles, however, utilize flow gates to keep down from shifting. Despite being more expensive to produce, this has proven to be the warmest and most efficient design. The Super Down Sleeping bag uses vertical baffling with additional robust zipper, shoulder, and halo baffles to minimize heat loss. This allows you to utilize your bag in a wider range of temperatures.
KUIU chose all the most advanced ingredients and construction technologies to make the most advanced sleeping bag on the market. We use water repellent 100% Polish Goose down, TORAY Stunner Stretch™ Micro Ripstop 12 D Nylon fabric, and true vertical baffles to create such a high performance bag. This bag is designed by the hunter, for the hunter.