--- title: "Not all down is the same. Everything you need to know about it" description: "Are you choosing a down sleeping bag, jacket or another product and wondering which down is better, how it insulates and how it behaves in damp conditions? Take a look at our article." canonical_url: "https://gramino.com/blog/everything-you-need-to-know-about-down" last_updated: "2019-02-03" --- # Not all down is the same. Everything you need to know about it Authors: David Czempka Date: 2019-02-03 Are you choosing a down sleeping bag, jacket or another product and wondering which down is better, how it insulates and how it behaves in damp conditions? Take a look at our article. As recently as 150 years ago, you'd have kitted out a freezing expedition with heavy fur. Were people back then simply unaware of down's brilliant insulating properties? Did they lack the fabrics or technology to process it? Today, down is one of the best thermal insulators for bedding and clothing. We've taken it so far that we now build dedicated farms for cultivating and collecting it, carefully measure its quality, and then stuff it into skirts, hats, comforters, and [sleeping bags](/c/sleep/sleeping-bags). So what makes down so special compared to other available materials? How does it actually insulate, what are its pros and cons, and where does it come from? ## Down feathers Although I mention down in the intro, what I really mean is a specific type of feather – down feathers. This is the type that really excels at thermal insulation. Even a reasonably observant eye can spot the difference in structure. Only certain bird species grow down feathers, found beneath the outer layer of contour feathers. Down feathers are amazing because their structure can trap air molecules. In practice, that means when you pull a down garment out of its compression sack, it starts to puff up (gaining **loft – fluffiness**) and forms a cushion of air. Once you put on a down jacket or crawl into a sleeping bag, you start warming that air cushion with the body heat you radiate. At the same time, the air layer blocks cold from reaching your body. 1 gram of down consists of **500–1,000 tiny clusters**, depending on their size. Compared to synthetic materials, down has the ability to slowly absorb body moisture. Even though it might not seem like it, that's an advantage that helps you feel more comfortable. Moisture passes through the down and gets carried away, so the microclimate stays much more pleasant and you feel dry. Moderate moisture also helps the down regenerate and restore its original loft. What's remarkable is that even a few grams of down can take up quite a lot of space once it's puffed up – creating a thick layer of air. Conversely, if you crush the down and squeeze the air out, it **takes up minimal space**. Down retains its ability to compress and re-loft repeatedly for many years – with proper care, that can easily be 20–30 years. But even down has its Achilles' heel, and that's water. On contact with water or heavy water vapor, its structure collapses and mats down. In that state, it can no longer trap air, so it completely **loses its ability to hold heat**. Add in a fairly long drying time, and a wet sleeping bag or down jacket is definitely not something you want to experience on your travels. That's why gear filled with down needs to be protected from soaking through in tough conditions – inside your backpack, for example, with [dry bags](/c/gear/drybags-and-organisers). - [Sea To Summit Ultra-Sil Dry Bag](/p/sea-to-summit-ultra-sil-dry-bag.md) - [Liteway Litebag With Dyneema®](/p/liteway-litebag-with-dyneema.md) - [Sea To Summit eVac Compression Dry Bag](/p/sea-to-summit-evac-compression-dry-bag.md) - [Sea To Summit Lightweight Dry Bag](/p/sea-to-summit-lightweight-dry-bag.md) - [Hyperlite Mountain Gear Side Entry Pod](/p/hyperlite-mountain-gear-side-entry-pod.md) Besides down feathers, the chambers of down products are also filled with tiny feathers that help take up more space. You'll come across down-to-feather ratios ranging from **80/20 to 95/5**. As mentioned, down feathers are the magic insulator, so the higher their percentage, the better. That said, a small share of feathers should always be kept in the mix. ## What is cuin and how is it measured? The key parameter for judging down fill quality is **fill power**. To make things more complicated, there are at least 10 standards you can measure it by. A single sample can easily yield ten different values. Sadly, in many cases the final product doesn't tell you which standard was used to determine the fill power, so it's worth taking that number with a grain of salt. In simple terms, the measurement works like this: down is placed in a cylinder and loaded with a weight. The resulting volume the down occupies in the cylinder is converted into the standard's units, and that gives you the fill power. [Video](https://youtu.be/UTTLDl_Y98U) ### The standards usually differ slightly in several parameters: - how the down is prepared - the weight of down in the cylinder - the diameter and height of the cylinder - the weight of the load - how long the weight is applied Test results from different standards can be converted between each other, but they'll unfortunately always be somewhat skewed, since this doesn't account for differences in how the down was prepared before testing – which plays a significant role. Don't worry, though – the most commonly used standards, at least where we're based, are still the **European and American** ones. Both measure fill power in cubic inches (in³) per ounce (oz), most often labeled on products as **cuin** (**cu**bic **in**ches). When measuring the same sample, the resulting fill power under the US standard will be about **7–8% higher** than under the EN standard. **So we can call the European standard the stricter one.** Don't worry that a product filled with 500–600 cuin down won't perform well enough. To meet the conditions it's designed for, the manufacturer simply fills it with more down. That shows up in its packed size and overall weight. Lower fill power suits those working with a tighter budget. ##### But if you're after a [sleeping bag](/c/sleep/sleeping-bags), [quilt](/c/sleep/quilts), or [down jacket](/c/clothing/men-s-clothing/men-s-jackets) with minimal weight, good packability, and great performance, down with 800+ cuin is the right choice for you. - Cuin 500–600 EU (530–640 US) – acceptable quality for average products, lower price - Cuin 600–700 EU (640–745 US) – minimum quality for higher-performance products - Cuin 700–800 EU (745–850 US) – good quality, great performance-to-price ratio - Cuin 800+ EU (850+ US) – high quality, higher price [Video](https://youtu.be/G62Y7Xcx75Y) ## Where does down come from, and which type is better? About **99%** of the world's down production is obtained as a natural byproduct of poultry farmed for meat – most often geese and ducks. Farming birds purely for down wouldn't make financial sense. Before being used in products, the down is carefully sorted and cleaned. And what about the remaining one percent? The other way to obtain down is before the birds are slaughtered. Here you need to distinguish between two very different methods, especially from an ethical standpoint. The first, legal method (under EU law) is **gathering**, which happens during the molting period and requires special handling of the birds. The other is **live-plucking** birds. This method is illegal in the EU and has also been rejected by every major organization involved in testing and labeling down. China has long been the world's largest down producer**.** No surprise, since it's also one of the biggest consumers of duck and goose meat. According to a 2006 study by IDFL (an international down-testing laboratory), Chinese down accounted for **76.7% of global production**. Other major producers include France, Ukraine, Hungary, and Poland. **Goose down** is generally considered higher quality than duck down. Goose down clusters tend to be larger, giving them better fill power. Since geese are typically older when their down is collected, goose down tends to be **more durable and long-lasting** than duck down. **That said, it's not always clear-cut – you can find ducks with very high-quality down and, conversely, geese with lower-quality down.** Down can also be collected **from wild birds**, specifically the down they use to line their nests. This process is too labor-intensive to be more than a niche source. Eiderdown is worth a special mention, reaching values of up to **1,200 cuin**. It doesn't suit outdoor gear chambers particularly well, though, because it clumps together easily – a trait it evolved as protection against wind. It's used more in luxury comforters and pillows. A handful of farms that collect down from waterbird nests can be found in Iceland and other Nordic countries. Roughly 16 grams of down can be collected from a single nest. It's no surprise, then, that only **a few thousand kilograms** of such high-quality down are produced each year. ### References and links [http://www.idfl.com/info/](http://www.idfl.com/info/) [https://www.edfa.eu](https://www.edfa.eu/) [https://en.wikipedia.org/wiki/Down_feather](https://en.wikipedia.org/wiki/Down_feather) [https://en.wikipedia.org/wiki/Moulting](https://en.wikipedia.org/wiki/Moulting) - [Liteway Choonie Apex](/p/liteway-choonie-apex.md) - [Montane Anti-Freeze Mitt](/p/montane-anti-freeze-mitt.md) - [Montane Anti-Freeze XT Hoodie](/p/montane-mens-anti-freeze-xt-hoodie.md) - [Cumulus Plancklite Men's](/p/cumulus-plancklite.md) - [Cumulus Panyam 600](/p/cumulus-panyam-600.md) - [Cumulus Lite Line 400](/p/cumulus-lite-line-400.md) - [Patizon G 400](/p/patizon-g400.md) - [Patizon D 590](/p/patizon-d-590.md) - [Liteway Simple Quilt 870 FP 10D](/p/liteway-simple-quilt-870-fp-10d.md) This post is also available as [HTML](/blog/everything-you-need-to-know-about-down). ## Sitemap See the full [sitemap](/sitemap.md) for all pages.