Roads Rivers and Trails

Dream. Plan. Live.

Monthly Archives: January 2021

Down vs. Synthetic Outerwear

by: Will Babb

Comparing down versus synthetic insulation in outdoor outerwear

If you ever want to waste an hour of your time, ask a gear junkie about the difference between down and synthetic, sit back, and listen to a monologue about the pros and cons of each. If that doesn’t sound like the best use of your time, spend a few minutes reading the rest of this blog for a brief overview of anything you might need to know. I’ll start off by defining a few things, dispelling a few myths, and sharing some key pieces of information.

When it comes to down insulation, the big talking point is always fill power. This isn’t an enigmatic concept only the experts know about; it’s actually fairly simple. The fill power refers to the number of cubic inches of down in one ounce. A piece with 700-fill down will have 700 cubic inches of volume per ounce of down. A big myth is that the higher the fill, the warmer the piece. This is sometimes, but not always, true. Fill refers to the quality of the down, but not how warm it is. Warmth has just as much to do with the amount of down or the way it is packed into the piece as it does fill power.

There is a right time and place for down or synthetic. Typically, synthetics perform better in wet conditions because they will continue to insulate even after they are saturated. However, synthetics tend to be heavier and less compressible than down, although they usually make less of a dent in your wallet. Down pieces, on the other hand, are highly compressible, lightweight, and sometimes as expensive as a flatscreen TV. The downside (pun intended) is that these pieces don’t insulate when wet. Even hydrophobic down, treated with a solution such as DownTek, won’t perform as well as synthetics once it gets wet.

Additionally a down garment doesn’t actually contain feathers. Instead, the loft comes from down plumules which are incredibly light and airy and will pack down smaller. These featherlight (another pun!) down clusters are what give your jacket all that fluff, without the annoyance of quills poking your skin. If you’re in the market for a new winter jacket or sleeping bag, it’s important to consider all of those factors before making a purchase. The conditions you’ll be using it in and how important weight and pack size are to you might determine which one is best for you.

Most down pieces will be either duck or goose down, with goose down being the higher quality but more expensive of the two. Many outdoor brands such as Rab and Sea to Summit are using sustainably sourced down certified by the Responsible Down Standard, which ensures ethical treatment of birds.

Almost all down pieces will be baffled, which give them the quilted look. These baffles prevent the down from piling in one end of the sleeping bag and distribute the insulation evenly. These baffles are made in one of two ways, either via sewn-through construction or box wall baffling. Sewn-through construction is the most common method used in gear. The fault in this is that you are left vulnerable to cold spots, whereas box wall construction eliminates this problem but results in a heavier, less compressible, and more expensive piece of gear.

I briefly mentioned fill power above, but there’s a bit more to it than just numbers. Most outdoor apparel or sleeping bags will have fill power somewhere between 650 and 850, with some extremely high-quality garments having fill as high as 950- or 1,000-fill. A typical piece might have 650-fill; anything above 750 would be considered lightweight and more suitable for backpacking. As with most gear, the lighter pieces and higher fill are almost always a bit more expensive.

With higher fill power, jackets require less down to create the same amount of insulation. For example, a piece with 850-fill power might only need three ounces of fill to create just as much loft as a 650-fill power piece packed with five ounces of down. To add confusion, down is either rated by a European or US standard and the standards are slightly different. Generally, the US has a lower standard, so a Patagonia jacket labeled as 850-fill by the US standard is equivalent to a Rab jacket rated at 800-fill by the European standard. A good rule is to subtract 50 fill power from the US number to get an approximate European equivalency.

Fill weight is an often-overlooked specification when people are comparing items. Fill power only tells you the quality of the down used, but the weight refers to how much down there is. The heavier the fill weight, the more down is in the garment and the warmer it will be. It is important to remember the connection between weight and power though, as both contribute to the overall warmth of the jacket.

Down jackets or sleeping bags are a great choice when lightweight, packable gear is important, but the chances of wet weather are low. For activities like backpacking or mountaineering, down is a good choice and worth the extra money. Down can always be layered with a waterproof piece to protect it from the elements. I tend to prefer down because I usually need lightweight gear and love having the ability to pack a jacket into its own pocket or compress my sleeping bag to the size of a water bottle.

Synthetic insulation is much less complicated than down. There’s no fill power or complicated terms to understand; synthetic insulation keeps you warm even in wet conditions and it’s that simple. There are many types of synthetics; almost every company has its own proprietary synthetic. The differences between Primaloft, Cirrus, or Polartec insulation are minimal; some breathe better than others, but it would take far too much detail to cover the minute differences in this blog. Many companies are making recycled synthetic fill for the conscious consumer. It’s still important to look at fill weight with a synthetic piece. How much insulation is actually in the garment is crucial.

Your gear should last you for a long time if it is cared for properly. Synthetics are much easier to care for, whereas down requires delicate washings, special detergents, and appropriate storage. A lot of people don’t consider this until after they’ve purchased their gear, but if ease of care is important to you, don’t forget this factor when making a decision. If you’re going to be adventuring in wet conditions or will spend your winter skiing day in and
day out, a synthetic piece would probably suit you better than down. It’s that superior performance after it gets wet that gives synthetics the edge when weight is less important than insulation.

As of yet, there are no synthetic materials that can compete with the high warmth to weight ratio of down. If you’re looking for a crazy light and packable piece that is still useful in wet conditions and inexpensive, you might need to look in an alternate universe. There is no perfect piece to suit all of your needs, so you might need to make some compromises on what you want. You’ll have to weigh the options and decide what factors matter the most to you, and then see if down or synthetic will fit those prerequisites. There are pros and cons to both down and synthetic gear, but it is not as intimidating as it sounds to choose between the two! Do your research beforehand and you should walk away with gear that will keep you warm and happy all winter long.


*Get the full gear ninja training and become an expert with these other Down blogs and videos:

Sleeping bag breakdowns by the Goatman: read here

Cleaning your down with the Bear: read here

Hydrophobic Down test video: watch here

*these blogs are not revised from their original post and may have outdated product information.