The Mountain Light 20° is Eastern Mountain Sports’ high end technical sleeping bag, designed for 3 season use on the most rigorous adventures. Ultralight fabrics and high fill power down combine with a fitted mummy shape to provide incredible warmth in an extremely compressible form factor.
For the next generation of this iconic bag, I focused on providing only the necessities and stripped it back to pure, uncompromising function.
We chose an ultra high quality, lightweight 20D Ripstop Nylon shell and replaced the 600 Fill Power down of the previous generation with 750FP to provide more loft, lighter weight, and better compressibility.
A redesigned hood drawcord is accessed from inside the bag, keeping it out of the user’s face through the night.
I also paired down the exterior design, leaving only the distinct vertical baffling stitch lines. The overall shape of the bag was updated to include a side baffle that raises the zipper away from the sleep surface, helping eliminate cold creep. This also leads to a more 3 dimensional overall shape that allows for maximum loft from the down and retains heat more efficiently.
Branding design has been standardized throughout the Sleeping Bag range, with temperature rating, fill material, and sizing displayed on compression sacks and storage bags for easy in-store selection.
On a technical bag like the Mountain Light 20°, the details are king. The interaction points like the internally accessed hood drawcord and snap closure at the top of the zipper play a vital role in a satisfying user experience.
Getting the baffle sizing correct is paramount to maximizing loft and warmth of the down. Too much room and the down can’t fill the space, but too little and the down is left is compressed, preventing those wonderful heat trapping air pockets from forming.