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6 Alternative Jacket Insulations That Aren’t Down

Not all jackets are filled with feathers.

Blue Bison

You finally swapped out your winter clothes from your summer/fall clothes and pulled out your long lost ski jacket. After you look it over, you quickly realize it’s seen better days and that it’s for an upgrade. There are tons of jackets to choose from, but there’s an aspect that you’re likely overlooking: what do you want your jacket to be made of? This is a question that consumers need to answer now, either in person or online when they go shopping for a new winter jacket. For years, all you had to do was decide if you wanted a synthetic jacket or a down jacket, but now there are tons of other options, and many more decisions to make.

A handful of brands are now offering alternative insulation materials that range from sustainable to strange, and oftentimes offer different pros and cons than standard down and synthetic insulations. To help aid in your purchasing decision, we pulled together everything we know about the new fluff.

Llama Insulation


Cotopaxi is a brand that’s focused on doing good, so it’s logical that it would produce environmentally-friendly insulation. Its version is called Alti Insulation, and it’s made of llama wool. The material functions well as an insulator and offers many of the same traits that merino wool does. Cotopaxi sources wool from llamas farmed in the high plains of the Bolivian Andes — much the same way many brands source merino wool from sheep that live in the high elevations in New Zealand. It also helps that llama insulation is hypoallergenic, durable and maintains warmth when wet. It’s a 50-50 blend that separates coarse llama hair from fine hair, similar to de-hairing cashmere. You can see the final product in the Kusa Collection as jackets and blankets.

Learn More: Here

Bison Fiber

Like Cotopaxi, United by Blue is committed to sustainability and giving back to the community. For every product sold, one pound of trash is removed from the oceans and waterways around the world. The team is constantly innovating to find the most sustainable fabrics to use in its apparel and gear. Bison fiber is the latest sustainable fiber that the brand has integrated into its product line.

Dubbed BisonShield, UBB’s unique insulation is a blend of 50 percent bison fiber and 50 percent recycled polyester. It’s the most sustainable down-alternative jacket the brand has ever produced. BisonShield insulation regulates body temperature, is hypoallergenic, warm when wet, lightweight and flexible and uses a supply chain that takes advantage of a fiber that’s otherwise considered a waste byproduct by the ranching industry.

Learn More: Here

PrimaLoft Bio

PrimaLoft is a key player in the world of synthetic insulation, and one of its newest types, Bio, took nearly five years of development. “We think of ourselves as an advanced materials company, so our core strength is polymers and textiles. Our thought process was ‘It’s going to be virtually impossible to police the world,’ so we wanted to go at its source,” says Mike Joyce, CEO of PrimaLoft.

Alongside experts from various industries, the brand found that to achieve a more sustainable product, modifying the synthetic polyester was the best play. “We modify the polymer so it’s more attractive to the natural microorganisms that reside in landfills and oceans,” Joyce says. “A standard polyester is not a material that microorganisms will gravitate towards.” So the brand created a material that microorganisms are attracted to in order to speed up the decomposition process. “They break it down into natural materials such as water, CO2, methane and what we call biomass.” Does this mean it’ll start to degrade in your closet? “No, it won’t because oxygen doesn’t trigger it. You have to be in an environment where microorganisms exist,” like the ocean or a landfill, Joyce says. After rigorous testing, PrimaLoft claims that Bio is 84 percent degraded after 400 days compared to standard polyester, which is just two percent degraded.

Learn More: Here


Wool is widely used for next-to-skin garments, but not so much as insulation. While there are a handful of companies that are creating wool-insulated jackets, pants, shirts and more, Ortovox has committed to using it across its entire jacket line. The brand uses what it calls Swisswool insulation. Sourcing the wool is an incredibly hands-on process. Ortovox works exclusively with Swiss farmers to buy their second shearing wool, which is course, stiff and scratchy, and not particularly suited for sweaters or base layers. However, those very traits make it a good insulator.

After sourcing the material from various collection points around Switzerland, the wool is weighed and farmers are paid in cash for their crop (much the same way you’d buy tomatoes at a farmer’s market). This second shearing wool was previously discarded or burned because it cannot be woven. Ortovox thought creatively and turned it into a product that is both sustainable and high-performance.

Learn More: Here


We’ve written extensively on 37.5 and its ability to keep you cool during workouts, sleep and throughout the day. It’s also shown up in insulating jackets; Portland, Oregon-based Nau previously integrated 37.5 into its jackets as an alternate for goose down to capitalize on its ability to stay warm, dry quickly and is resist odors, which is a concern when a base layer or insulation layer is so close to your skin.

Learn More: Here


Yes, you read that right: flowers. Introduced by a brand called Pangaia, FLWRDWN is made of dried wildflowers and a biopolymer that are infused with aerogel. Pangaia claims that it took more than ten years to develop and that the sourcing process relies on a system of regenerative agriculture that contributes to habitat restoration, butterfly conservation and the reduction of greenhouse gases. Plus, the flower fluff is both breathable and hypoallergenic.

Learn More: Here

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