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Down Buying Guide: Winter is the time to get down


A down feather.
The down feather is a layer of feathers found under the exterior feathers of geese and ducks.

Down. That fluffy stuff that waterfowl like geese and ducks have. Their wonderful, insulating down feathers have been keeping us humans nice and toasty warm for a long time now. And today, it’s all over the place: in our sleeping bags, pillows and, among other things, our jackets! The latter is what we’re going to talk about today.

More specifically, we’re going to address the following questions regarding down jackets:

1) What constitutes a quality down jacket?

2) Which manufacturers actually put thought and consideration into the origin and production of down?

3) What do terms like cuin, loft and fill power have to do with it?

4) And finally, what is a down jacket for and when should you choose an alternative instead?

So, let’s begin by differentiating between feathers and down. I’m sure you’re all quite familiar with feathers. Those are the things that make birds so pretty and colourful! Down, on the other hand, is either grey or white and is the layer of feathers found under the exterior feathers of geese and ducks. In contrast to feathers, down has a three-dimensional structure similar to a snowflake. Plus, it is significantly lighter than a feather.

Cuin, grams or %?

There are three different criteria that should you take into consideration when purchasing a down jacket.

  • fill power (also: loft, cuin)
  • the amount of down
  • the down to feather ratio (e.g.: 95/5)

So, what’s the deal with down fill power? This indicates the down’s ability to bounce back and ‘loft’ after being compressed. It is expressed in cubic inches. So, “cuin” = cubic inches. Easy, right? Well, not exactly. But, let’s not go into all the technical mumbo-jumbo. Discussing in detail how cuin is actually determined and measured would go beyond the scope of this blog post. What is important for you to know, though, is that a down jacket with a fill power of 500 cuin is a jacket you can actually use. As you can probably imagine, the fill power rating reflects the quality of the down as well, with 650 cuin being a very good rating and 750-900 being excellent.

The amount of down affects the degree of insulation as well. The 280g Mammut – Broad Peak Light Jacket, for example, has a significantly lower insulation performance than the 630g Mountain Equipment – Vega Jacket. The downside to heavy jackets is their larger pack size and the diminished range of motion.

And, finally, the down-to-feather ratio plays a very significant role as well. If a jacket has 100 grams of insulation and a mixture ratio of 90/10, this indicates that the jacket has a total of 90 grams of down and 10 grams of feathers. The down-to-feather ratio affects both the weight of the jacket and its thermal efficiency. This is due to the fact that feathers are heavier than down, don’t trap air as well and are thus incapable of providing the same level of warmth as down.

The Michelin Man

Dauenjacke und der optische Michelin-Männchen Effekt
The Michelin Man effect

The down in down jackets is divided up in to different baffles or lines in order to prevent the down from shifting. This allows warmth to be distributed across your upper body, but it also gives you a puffy look, one quite reminiscent of the loveable Michelin Man. The seams are usually sewn through. But this can result in a loss of heat through cold spots. This is why higher-end models have a layer of fabric sewn in that prevent cold air from penetrating the interior. There are also jackets, such as the adidas – TX Climaheat Agravic, that prevent the loss of heat through cold spots by way of an overlapping construction.

Small, medium or large?

Never underestimate the importance of the size of your down jacket. If you’re jacket is too big, not only will it look bad, but it will also make it easier for heat to escape. The collar should be particularly close fitting so that any warmth that has been retained on the interior won’t be lost. Your jacket shouldn’t choke you, though, but rather fit snugly around your neck.

The pros and cons of down insulation

There are alternatives to down, such as synthetic products. The following table shall provide you with an overview of the advantages and disadvantages of each material.

DownSynthetic insulation
+ very lightweight– somewhat heavier than down
+ extremely small pack size– bigger pack size
+ more comfortable interior via moisture transfer– less moisture transfer
+ long lifespan if properly cared for– shorter lifespan than down
– loses insulating ability when wet+ retains insulating ability when wet
– absorbs moitsture from the inside and outside+ retains insulating ability when wet
– dries slowly+ quick drying

Areas of use for a down jacket

Two mountaineers wearing down jackets in an ice field in the mountains.
For mountaineering, a down jacket with a small pack size is ideal

Since down is warm and simultaneously incredibly lightweight and packable, it’s perfect for travel in cold regions or when you don’t have a lot of room to spare in your pack. Plus, with a down jacket, you’ll no longer need to worry about freezing during your tea or coffee break!

Down jackets will even fit in a MTB pack, so you’ll be able to enjoy a beer outdoors after a long day of exhilarating downhills. It’s a great thing to have as a belayer as well whilst you watch your lead climber move up the rock. And even if you head out to Fontainebleau at the cooler times of the year for some bouldering, you’ll be happy you brought along that toasty warm down jacket.

In short: a down jacket is a good thing to have when

  • it’s cold out
  • it’s not raining and you’re not extremely active
  • you have little room to spare in your pack and every gram counts

Down: wannabe synthetic?

There are manufacturers who treat their down in order to make it handle moisture better. The advantage here is that the treatment makes the down hydrophobic, which will prevent it from clumping together when exposed to moisture. This means that the jacket won’t absorb moisture from the inside, either, which results in an interior environment similar to that of a synthetically insulated jacket.

Good and evil down

Since down is a product derived from an animal, it has to get from the animal to the jacket in some way, shape or form, right? Unfortunately, some of these methods for obtaining down are very dodgy, to say the least. Some down feathers are collected through something called live plucking. As you can imagine, live plucking is incredibly cruel and causes the animals a lot of pain and distress. The other “evil” kind of down is obtained during the production of foie gras (“fatty liver”). This is the extraordinarily cruel process of force feeding ducks and geese and is just as horrible for the animals as it sounds. Thankfully, it’s banned in a large number of European countries, but not in all of them.

Now, many manufacturers advertise that their down is obtained not from foie gras production but from animals slaughtered for the food industry. Still, it is incredibly difficult to guarantee, since there are several individual operations involved in the production of down. And, let’s face it: there are still plenty of black sheep out there. And, when manufacturers get the final product, there’s no way to tell where the down originated.

HAGLÖFS Women's L.I.M Down Hood - Daunenjacke
The HAGLÖFS-Women’s L.I.M Down Hood – down jacket with a tracking code

For this reason, five manufacturers have teamed up with animal rights groups to carry out inspections in order to definitively determine the origin of the down. These are: Vaude, Patagonia, The North Face, Mammut and Jack Wolfskin. Other manufacturers, such as Mountain Equipment, carry out their own random inspections of the supplier’s down for more transparency. Mountain Equipment calls this the Down Codex. More and more manufacturers are also beginning to offer tracking codes, which can be used to trace back the origin of the down. An example of this is the Haglöfs – Women’s L.I.M. Down Hood.

Ultimately, it’s your decision as the consumer to decide what you use your down jacket for. For all the positive qualities of a down jacket, there are quite a few dodgy bits as well that you definitely need to consider when buying a down jacket.

Find warm Down Jackets >>

Teile den Artikel mit anderen Bergfreunden

Bergfreund Florian K.

5 Comments on the Article

  1. mary 15. Mai 2021 09:08 Uhr

    very professional explanation. learnt a lot. thanks for the great job

  2. Annie 15. Mai 2021 09:08 Uhr

    Thanks for that, I did learn a lot. However, I'm wondering why Rab Equipment isn't mentioned as a company. They claim to use RDS (Responsible Down Standard), and the RDS' sole aim is to ensure that the used down doesn't involve animal cruelty. Should Rab be added to the list above, or is there a reason they're excluded?

  3. Jason 15. Mai 2021 09:08 Uhr

    Hello- If a goose/duck is a water foil and therefore their feathers are naturally hydrophobic, has anyone ever pondered why, other than being able to charge more (ex: RDS), manufacturers apply a hydrophobic sealant to something that is already hydrophobic? I know Western Mountaineering doesn’t and their bags are amazing.

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