Of course, you can’t simply fill a sleeping bag with down as if it were a pillow and expect top results in performance and comfort. Do this and the down would shift throughout the sleeping bag, sliding around, collecting in certain areas while thinning out or disappearing completely in others. This would lead to serious cold spots and ineffective insulation, not to mention a loss in comfort.
This is why our down sleeping bags rely on a baffle or chamber construction. This construction evenly distributes the down fill with a series of baffles, thereby effectively preventing the down from shifting around in the bag.
The simplest construction used is the H Chamber construction.