The next generation of sleeping bags

Optimizing warmth with the Spider Baffle System

To prevent down from shifting and producing cold spots, sleeping bags are usually made with inner walls called baffles. The Seamless Down Hugger Series is the world's first sleeping bag to remove those traditional baffles. This radical construction technique produces a sleeping bag with a single, continuous chamber which allows the down to loft to its fullest potential. While optimizing the heat retention of down, the baffleless construction maintains the lightweight, packable and elastic properties that Montbell's sleeping bags have become known for.

We asked ourselves, "What can we do to optimize the heat retention of down?" Our attention turned to the baffle. In standard sleeping bags, there are small compartments constructed with walls (baffles) that keep down in place and prevent the formation of cold spots. Our idea was that by eliminating these baffles, down would be able to loft to the max, resulting in increased thermal efficiency.

One reason is loft improvement. If down has more room to loft, it will trap more air, resulting in more warmth. Another reason is enhanced heat retention through reduced sewing holes. Sewing baffles into a sleeping bag creates perforations in the face fabric, which will allow warm air out and cold air in. By drastically reducing the amount of sewing holes, we are able to create a sleeping bag that is more efficient at trapping air. However, in order to make our idea a reality, we had to create a way to hold the down in place without baffles. This was the biggest hurdle we faced when trying to create the next generation of down sleeping bags.

1. The baffle is removed.

2. Space is increased.

3. One large chamber is created. Down compressed by the baffle is allowed to loft.

4. Down lofts to its max heat-retaining potential.

Spider Yarn trapping down

When looking for a suitable replacement for the traditional baffle, we received a little inspiration from the spider. The thought was, "If we could make a web inside the sleeping bag, it would suspend and hold the down in place." Based on this initial concept, work began on developing a specialized yarn that could trap the down. We were able to successfully lay this Spider Yarn inside of the entire sleeping bag to evenly suspend the down throughout. This revolutionary new construction is called the Spider Baffle System.

Spacious, baffleless chambers

Maximized down loft
A spacious chamber is created without baffles. The down is unobstructed in its pursuit to loft and fill the spacious chamber, where it able to store ample amounts of air.

Minimizing seams

Retains warmth
Baffles require sewing. By eliminating those baffles, we're able to create a sleeping bag with almost no stitching holes on the face fabric. This delivers an almost airtight construction that keeps warmth in and the cold out, resulting in a very thermal-efficient sleeping bag.

Spider Yarn

Traps down and prevents cold spots
Spider Yarn holds a set amount of down evenly throughout the sleeping bag. Even if pressure is applied, a certain amount of the down remains in place without shifting.

The elastic threads pull the bag in closer with less excess space to gently hug you with heat-retaining comfort.

The mechanical stretch fabric combined with the elastic threads create a sleeping bag that moves with you and limits constriction to promote comfort.

The Super Spiral Stretch System is a specialized feature utilized on the interior of Montbell sleeping bags. The mechanical stretch fabric and elastic threads provide excellent stretch (maximum stretch rate of 135%) to deliver a close fit while allowing you to move. The sleeping bag gently hugs and stretches with you as you move in your sleep, and the close fit limits excess space to delivering more efficient heat retention.

Highly heat-retaining EX Down

The Seamless Down Hugger Series utilizes EX Down, which is sourced from waterfowl living in regions with extreme temperature differences to obtain larger down balls. This high-quality down features long barbs that store ample amounts of air, resulting in insulation that is warm, light and packable. EX Down features excellent loft resilience, ensuring long-lasting warmth for many adventures.

900 Fill Power EX Down
Super high-quality 900 Fill Power EX Down provides an outstanding warmth-to-weight ratio.

800 Fill Power EX Down
High-quality 800 Fill Power EX Down provides an excellent warmth-to-weight ratio.

Ultralight & supple Ballistic Airlight

The ultra-thin nylon fabric shows impressive strength for the weight. The thin, supple fibers do not interfere with down's ability to loft.

Easy packing with the Tapered Spiral Stuff Sack

Features a wide opening to allow for easier packing. Because the fabric stretches horizontally and vertically, it's possible to alter the shape of the sleeping bag to some degree so it fits in the available space of your backpack.

A. Hood adjustor: Provides an adjustable fit and helps keep cold air from entering around the face.

B. Tunnel hood: Shaped to reduce exposure around the face and enhance heat retention.

C. Neck baffle: The insulated, tube-shaped collar keeps your neck warm and comfortable.

D. Auto-locking zipper: Stays in place even while you move in your sleep. Equipped with anti-snagging parts.

E. Triangle gusset: Constructed at the end of the zipper to prevent fabric tears.

F. Draft tube / insulated flap (interior side of zipper): Helps block out cold air.

High-quality 800 Fill Power EX Down is combined with an ultralight shell material to create a lightweight, packable sleeping bag. The Seamless Down Hugger 800 is designed to let down loft to the max, while providing the stretch that Montbell sleeping bags are known for.

Seamless Down Hugger 800
Deliver warmth at a light weight.
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Seamless Down Hugger 800 Women's
Features women-specific design.
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Seamless Down Hugger 800 Half Length
Use with an insulated jacket for an ultralight sleep system.

Seamless Down Hugger 800 Thermal Sheet
Adds warmth to your sleeping bag.

The bag keeps the down dry through exceptional weather and wind proofing to shut out the elements while releasing water vapor produced by your body while you sleep due to the materials superior breathability.

The zipper helps keep out water without the need for storm flaps, facilitating easier open and close while lightening the weight.

#1
Recommended if heading to mountains in winter.

#2
Designed for versatile use while backpacking or mountaineering in colder seasons.

#3
A year-round model, working great at higher elevations in summer and in milder winter conditions.

#5
Great for summer backpacking, camping, etc.

When you sleep, the weight of your body applies pressure and flattens the insulation, reducing heat retention. A sleeping pad will create space with the cold ground while adding heat retention and cushioning to maintain comfort. Using a cot will allow you to sleep away from the cold, hard ground. Sleep with a liner to increase comfort and protect your sleeping bag from sweat to ensure longer lasting use.