Differential cut and proportional differential cut
An elaborate 3D construction in which the inner lining is cut narrower than the outer shell fabric. This means that down chambers cannot be compressed by angled elbows or knees at night. Each down chamber is individually filled and precisely measured. This procedure requires more work steps than in a normal sleeping bag. The result, however, is optimal down lofting and the best possible use of the down.
But Exped goes one step further and makes individual cuts for every length and size. For example, the length M and L differentiate in the shoulder width and partly also in the foot area. Surprisingly, this more elaborate and time-consuming production is not a matter of course. The advantage, however, lies in the detail of the assumption that a longer body requires more space than a smaller body and the sleeping bags can thus provide optimal insulation. We call this the Proportional differential cut. It is important for us to consistently follow this concept and so we also offer wider sleeping bags in small sizes. So every person will find the right sleeping bag with us.
Most sleeping bags are simply constructed.
The differential cut as used by Exped.
Easy made seam used by most sleeping bags. We only use this seam technic for our Ultralite series to save as much weigth as possible.
With this technique 3 instead of only 2 fabric layers are sewn together and the seam is not visible from the outside. The inner walls are sewn with an additonal seam. A double seam is used to ensure that the down remains in the sleeping bag.
Thread does not wear and tear Seams do not wick moisture and condensation droplets into the sleeping bag
Finger and toe nails do not snag in seams
Should a seam fail, a second seam beneath prevents a hole.
Requires more material
Is slightly heavier as more material is usedMore elaborate, hence more expensive in production