The shape of the sleeping bag has a lot to say about its performance. Choosing the right shape will determine how comfortable you will be when you are using the bag. Here are the three basic shapes and their pros and cons:
The mummy shaped bag has the best insulation to weight ratio as it seals your body tightly and therefore is the most thermally efficient. The mummy shape gives the most warmth for its fill, but it also has the least internal space.
For those who wants some extra space, but still want a technical bag designed to withstand tough terrain, the egg-shaped sleeping bag is the right choice. Not as tight fitting as a mummy shaped bag, but much better insulating than a rectangular bag.
The rectangular sleeping bag is spacious and comfy as it provides extra space for those who really like to move inside the bag. All our rectangular models have an all-around zipper making it possible to use the sleeping bag as a blanket as well.