Sleeping Bag Construction
Good design tends to look simple, although the concepts and their execution may be anything but. For example all PHD's Ultralight bags including the Minimus bag use a walled construction rather than the easier stitch-through, just to give that little bit of extra insulation at each box line.
Our new Hispar bags have the same straight-wall baffles as the Ultralights. It is the lightest possible box-wall system, ideal when saving weight is the main objective.
The Baltoro, Diamir, and Xero ranges have a trapezoid baffle system, more complex in manufacture than most systems, but affording the best combination of excellent down control and light overall baffle weight. These are not the cheapest ways to construct bags, but when we have searched out the very best materials for PHD products, we take good care to maximise performance at make-up too. Nothing else makes sense.
Waterproofing sleeping bags
The standard outer fabric on our mountain sleeping bags is Drishell. Drishell is waterproof, highly breathable and very light. We think this is the best way to keep the down or synthetic insulation we use in our sleeping bags dry. However proofed outers are not perfect. Bags made with Drishell and similar fabrics do carry a small weight penalty (Drishell is the lightest we know of this type), and they do let water in at the stitch line (e.g. if you are sleeping in a puddle). Bags can also be made with complete taped outer shells, which will be proof against nearly all situations, but the weight penalty of an extra skin is considerable.
Our ultra light Minim sleeping bag range uses M1 and MX microfibres, fabrics that are extremely light. For customers who require a greater degree of waterproofing the Minim range is offered with the option of a Drishell outer.
For a much higher level of weather protection, the Xero, Diamir, and Hispar ranges are offered with the option of a fully taped shell in waterproof HS2.
If there's a serious danger that the sleeping bag will get wet we recommend using synthetic insulation such as is used our Zeta synthetic sleeping bags. They are designed for big wall bivouacs in damp conditions.
