Let's talk about down. How does it work?

Despite what you may think, down filling is not made from feathers. It’s made from goose or duck plumage, the fluffy insulation directly beneath the feathers. This is nature’s mid-layer, and despite our best efforts in science we’ve still not managed to create a more effective insulator for these applications.

So what does this fluffy insulation look like and how does it keep us warm? Down clusters are three-dimensional structures with thousands of filaments that criss-cross to create air space. Just as a sponge traps water, down clusters trap warm air while still allowing moisture and air to move through.  

What Is Fill-Power?

Down quality is measured by its fill-power, which in simple terms is a measure of the down cluster’s size. Larger clusters trap more air and are both warmer and lighter compared to lower quality down. The larger the down cluster, the higher the fill-power rating is. Fill-power represents how many cubic inches one ounce of down will occupy. If one ounce of down takes up 700 cubic inches of space, it is rated as 700 fill-power down. This signifies that less will be needed to achieve the same warmth as a 600 fill-power or lower quality down. In effect, you can achieve the same warmth rating with less down, so you have a lighter product.

In general, there are 3 different grades of down often used: 550 to 650 fill-power (these are high quality downs), 650 to 750 fill-power (which are performance downs), and 750 to 900 fill-power (these are premium downs — the lightest, warmest, and most expensive).

We wanted the best for our Beds so that you are able to get maximum performance from your gear, that is why we chose to use HyperDRY down from Allied. This premium down uses a natural wax-based compound to make it water-resistant.

DWR Treated Down

Conventional wisdom would have us believe that synthetic insulations outperform down in wet conditions, but conventional wisdom is wrong. While it is true that synthetics will insulate better than down when they are wet, it is also true that synthetics soak up water while down is naturally hydrophobic. It's simply much harder to get a down bag wet in the first place and with the recent invention of water-resistant down, that's truer than ever.

When down is first harvested from a duck or goose, it is water repellant - natural oils on the plumage make water fall away so that it can keep insulating. When down is processed and washed, some of these oils are removed. There have been improvements in washing methods to remove less of these naturally water-repellant oils, but generally DWR ("durable water repellant") treatments are used to restore down’s natural ability to repel water. There are several on the market right now, including the HyperDRY™ down from Allied we use in our products. This premium down uses a natural wax-based compound to make it water-resistant. It is both durable and fluorocarbon-free. We wanted the best for our Beds so that you are able to get maximum performance from your gear.


It is important to consumers and producers that down is responsibly sourced - meaning it does not come from animals that were subject to unnecessary harm. This includes standards that say down cannot be live plucked from birds, birds cannot be force fed, and producers have “holistic respect for animal welfare” throughout their lives. The Responsible Down Standard has become the worldwide certification for ensuring down is responsibly sourced. Zenbivy is proud to be RDS compliant. All of the down used in our products can be traced back to its source. When you receive your Zenbivy Bed or Light Quilt, checkout the Allied tag to track your down

If down isn't your thing, we offer synthetic options as well.

Check out our 29° Zenbivy Bed or our 40° Light Bed (Quilt + Sheet)

And this is no "dumbed-down" synthetic. These beds feature the exact build and same buttery-soft fabrics as the originals. We use a 1d/3d polyester synthetic that is as soft as it gets. All-in-all, they are as comfortable and as backcountry-worthy as our down beds.

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