Posted 1 August 2020

In Part Two we briefly mentioned “Waterproof” or Hydrophobic Down and here we add a little more background and detail.

We first will discuss the history and background of this down and then the effects on sleeping bag construction and weight.

History and Background

Waterproof or Hydrophobic down is not especially new. In the 1980s Northern Feather of Denmark, then the world’s largest consumer of down, introduced “Waterproof” to their range of quilts and sleeping bags. It was aimed at the quilts market which because of their daily use required more cleaning than sleeping bags.

Although heavily marketed it was not a success and a few years later was quietly dropped. The reasons given were that it reduced the softness and increased the weight of down and this softness to the touch and lightness of feel is an important feature of having a natural down filling. Waterproof/Hydrophobic Down the reappeared in the 2000’s offering the usual benefits of waterproofing and was highly marketed.

We have extensively explored the pros and cons and remain unconvinced of the benefits. Coating down with a DWR treatment stiffens the down and reduces the potential fill power.

Waterproof / Hydrophobic Down in Sleeping Bag Construction

High Quality, High Fill Power Down (ours is 880 Euro or 1000+ US) is naturally very hydrophobic, after all Geese live on Lakes and Rivers. Giving the Down a waterproof treatment does not add much to the offer and to us the extra cost is unjustifiable. Especially when we take into account that once a sleeping bag is wet - it is wet. It does not make a difference whether it contains DWR waterproofed or Natural Down. So for us, best practise would be to combine a dry bag with a waterproof cover.

As the use of Hydrophobic Down increases manufacturing cost, some sleeping bag manufacturers will compensate by using a lower fill power down which increases weight. We did an experiment and on our Arctic Bag it increased the cost by 25%. Completely unnecessary for a product that is considered by many as the best Arctic Bag available.


If it is likely that the bag will get wet we suggest you take one of our Pure & Dry bags with its Waterproof Cover which will keep out all the moisture in tents or snowholes.

If the bag is unlikely to get wet we suggest you take one of our superlight PURE models which are lighter and pack away smaller.

Waterproof outer covers and Vapour Barrier liners are also available.

For more information on this and other points mail