To prevent down from shifting and producing cold spots, sleeping bags have been traditionally made with inner walls called baffles. The Seamless Down Hugger series is the world's first sleeping bag to remove the traditional baffles. This radical construction technique produces a sleeping bag with a single, continuous chamber and allows the down to loft to its fullest potential. This technique doesn't affect the lightweight and compact nature that Montbell's sleeping bags have become known for. The next generation of sleeping bag is here!

A Eureka Moment: Eliminating the Baffles

We asked ourselves, "Is there anything we can do to improve down's ability to insulate?" As ideas were being tossed around, one idea that came up was, by eliminating the baffles the down would be unhindered and each down ball could loft/puff out to its fullest ability. This extra volume of air trapping down would thereby increase the insulative properties of the bag. However, the catch is baffles prevent down from shifting out of place. When down shifts out of place, cold spots can form. This is when there is a spot in the sleeping bag that has no down coverage.

If baffles prevent cold spots, how does eliminating them improve warmth?

Our first reasoning was that if you give down more room to loft, we increase the layer of trapped air and we can improve the insulating performance of the down. Another reason, since sewing baffles into the sleeping bag creates holes in the outer fabric, the sewing holes are ways for warm air to escape. By eliminating most of the sewing lines on the bag, we are able to trap more air. However, in order to make our idea a reality, we have to remove the baffles and come up with a way that could hold the down in place. This was the biggest hurdle we faced when trying to reach that next step.

Spider Yarn: a specialized thread that entangles down

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

Excellent stretch to provide better sleep

900FP High Quality Down

Ultralight Fabric

By combining the Spider Baffle System with a weatherproof breathable material, we've created a sleeping bag that maximizes down's ability to insulate. By seam sealing, we are able to effectively shut out water, keeping the down dry. We envision usage of this model in humid and wetter climates, especially when condensation on the interior of your shelter could compromise the down's ability to loft.

Fabric

Our state-of-the-art sleeping bag design achieves cutting edge performance without adding extra weight. The baffle-less outer design allows for unrestricted loft while the interior elasticized stitching pulls the bag closer to the body without making you feel constricted. Sleeping in the backcountry has never felt so good.

Seamless Down Hugger 800 Women's model

Our women's lineup of Down Hugger sleeping bags is designed to help women rest more comfortably. All of the technical aspects of this lineup are identical to our regular lineup, but does feature some key differences specifically for our female customers.

Seamless Down Hugger 800 Half Length

These half-length bags allow you to combine your puffy jacket with your sleep system, cutting down your trail weight even further.