Down insulation is a popular choice for summer sleeping bags, jackets, gloves, and other pieces of outdoor gear.
But, there are a whole lot of different misconceptions out there about down, which can make finding the right gear for your camping trip a major challenge.
To settle the debate once and for all, we’ve responded to some of the most common facts and myths about down so you can be more informed as you shop.
MYTH - Higher down fill power means more warmth
Perhaps the biggest myth about down that’s currently floating around on the internet is that a higher fill power means more warmth at night. While this is sometimes true, it’s not the case in every situation.
That’s because down fill power is a numerical representation of how much loft down has. Loft, or the fluffiness of down, is a way of describing how much air it can trap.
The more warm air down can trap, the better it can insulate you from the cold.
However, down fill power is only one-half of the warmth equation. Although high fill power downs do insulate very well, we also have to consider how much down insulation is actually inside a given sleeping bag or jacket.
For example, if two sleeping bags both use 800 fill down and one has 12oz (340g) of down insulation while the other has only 6oz (170g) of insulation, the heavier model is going to be warmer.
Alternatively, if you have 2 sleeping bags that each have 12oz (340g) of down insulation, but one is 900 fill power down and the other is 500 fill power down, the model with the higher fill will be warmer.
If we flip the script and have a 500 fill jacket with 12oz (340g) of down and an 800 fill jacket with only 3oz (85g) of down, the 500 fill model will actually be warmer, simply because it has more overall insulation.
Higher fill power has a better warmth to weight ratio, but we can’t universally say that it’s always going to be warmer than lower fill power down.
We also need to consider the down fill weight of any piece of gear we buy to ensure that we get a full picture of the insulating abilities of that sleeping bag or jacket.
FACT - There are different types of down
Gear manufacturers use either goose down or duck down in their gear. While this might not seem like a big deal (they’re both birds, right?), there are some differences between goose down and duck down that you should know about.
The primary difference between these types of insulation is that goose down clusters (the little puffs of down used to make jackets and sleeping bags) tend to be much larger than their duck-derived counterparts.
Larger clusters have more loft, or, in other words, they can trap more hot air.
As a result, high-quality downs above 750 fill power are almost exclusively made with goose down rather than duck down.
Of course, these larger goose down clusters don’t come cheap, so many manufacturers now make most of their 500 to 750 fill power down gear from duck down, rather than goose down to save you money.
Ultimately, if weight savings and compressibility are your primary concerns, then goose down might be your best bet. Otherwise, duck down is generally just fine and will likely be better for your bank account.
MYTH - Down fill is always better than synthetic
Humans have used down fill for warmth in cold environments for hundreds of years because of its excellent insulation abilities and fantastic warmth-to-weight ratio.
While down is often seen as the gold standard of insulation, however, synthetic fills are sometimes the better choice. In particular, synthetic insulation is better than down insulation in cold, wet locales.
Since down has no insulating ability when wet, swapping your down jacket for a synthetic model is generally best if you expect to encounter lots of rain or heavy, wet snowfall.
If you’d like the warmth to weight ratio of down but the weather-resistance of synthetic fills, you might want to consider a hybrid down sleeping bag or jacket, instead.
Hybrid down blends integrate both down and synthetic fills into a single product, allowing you to get the best of both worlds without sacrificing too much in terms of warmth, packability, or weather-resistance.
In cold, dry locations where weight savings are key, down is a solid choice. Otherwise, synthetic or hybrid down fill might be better if you’re traveling in wet conditions.
FACT - High quality down fill is made from clusters, not feathers
Some might argue that this is a semantic issue rather than a practical one, but it’s worth noting that high quality down fill is made from down clusters, not bird feathers.
A down cluster is a poofy collection of down fibers that looks a bit like the white head of a dandelion. These fibers all collect together and form a single fluffy ball of insulation that’s designed to keep birds warm in cold conditions.
Feathers, on the other hand, serve many different purposes on a bird’s body, from waterproofing to enabling flight.
What separates features from down clusters is that feathers have a stiff spine that runs down the middle, which is known as a quill. This quill is important for birds because it’s what helps attach the feather to the bird’s body and it allows for blood flow to the feather. But, it doesn’t have any real insulating value for the bird, or for our gear.
Why is this important information for you to know, as an outdoor enthusiast?
It all comes down to the quality of your gear. More often than not, a small amount of feathers accidentally makes its way into the down fill used in your jackets and sleeping bags. Of course, a small amount of feathers here and there isn’t anything to get upset about, but keeping the overall percentage of feathers to a minimum is important.
High-end down garments have a higher percentage of down clusters to feathers, or, in other words, they’re purer. These pure down fills (90% or more) are expensive, so lower fill power downs and more affordable options usually have a higher feather to cluster ratio.
If you want only the highest quality gear, you’ll need to do some research on the cluster to feather ratio of your down equipment as you shop.
This information isn’t always easy to find, so you may have to contact a manufacturer directly to learn more about the purity of their down insulation.
MYTH - Water-resistant down will keep me warm when wet
Water-resistant down is all the rage these days because it claims to fix down’s major drawback: that it doesn’t keep you warm when it’s wet.
To combat this issue, many gear manufacturers now treat their down fill with various chemicals – known as DWRs, or durable water-repellents – to give it some semblance of water-resistance when wet.
These treated downs sound awesome in theory, but they are limited in their effectiveness in the real world. Although water-resistant down can help in slightly damp conditions, nothing will make down perform well when it’s soaking wet.
That’s because there’s no chemical that can completely prevent down from clumping up when wet and there’s no chemical that can give down its loft back after it gets soaked in water during a rainy trip to Olympic National Park.
Indeed, the only solution in this scenario is to wait for your down sleeping bag or jacket to dry out after a rainstorm.
Water-resistant down is nice if your jacket or sleeping bag gets slightly wet in the mist or in a light drizzle, but it won’t make a real difference if your gear gets soaking wet.
FACT - Down fill lasts longer than synthetic fill
When you buy a piece of gear, especially one that’s as big of an investment as a down jacket or sleeping bag, you want to be sure that you’ll be able to use it for years on end.
The good news is that down insulation generally lasts much longer than its synthetic counterparts.
Although synthetic insulation does have its benefits, the thin fibers that it’s made of tend to break down fairly quickly after frequent use.
This is particularly true if you frequently pack and unpack your insulated gear into a stuff sack or backpack while you camp. Indeed, frequent compression breaks the tiny fibers in synthetic gear much faster than it wears down the clusters in down insulation.
As a result, down gear that’s cared for properly can often last 10 years or more, while you’ll often find that the insulating abilities of synthetic gear start to decrease dramatically after about 5 years.
All else being equal, down fill lasts longer than synthetic fill because down clusters are more durable than the thin fibers found in synthetic insulation.
Gaby is a professional mountain guide with a master’s degree in outdoor education. She works primarily in the polar regions as an expedition guide, though she can be found hiking, climbing, skiing, sailing, or paddling in some of the world’s most amazing places when not at work.