Why Bison Fiber?

American bison fiber possesses remarkable thermal properties that make it an excellent material for insulation and cold-weather apparel. Here are the key characteristics of bison fiber's thermal properties:

Exceptional Insulation

Bison fiber, particularly the downy undercoat, provides superior warmth and insulation in cold weather


. This exceptional insulating ability stems from the fiber's structure and composition, which has evolved to protect bison from extreme temperature variations in their natural habitats.

Temperature Regulation

One of the most notable features of bison fiber is its temperature-regulating properties. This characteristic allows bison to survive in diverse climates, from the heat of Texas to the frigid temperatures of South Dakota


. When used in clothing, this property helps maintain a comfortable body temperature across varying external conditions.

Fiber Structure

The thermal efficiency of bison fiber is largely due to its unique structure:
  • Fineness: The down fiber from adult bison measures between 17 to 22 microns, contributing to its softness and insulating capacity
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  • Staple Length: The typical staple length of adult bison down is about 1½ inches with a lot of "crimp" or kinks and bends, which allows for effective trapping of air pockets
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Thermal Performance

While specific thermal conductivity values for bison fiber are not provided in the search results, its performance can be inferred from its use and comparisons to other insulating materials:
  • Bison fiber is described as providing "seriously warm" insulation, suggesting low thermal conductivity and high heat retention
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  • The fiber's ability to keep a 1,000-pound animal insulated through harsh winter months indicates its exceptional thermal properties
    .

Practical Applications

The thermal properties of bison fiber make it ideal for various applications:
  • Winter Apparel: Bison fiber is increasingly used in high-performance winter jackets and accessories, leveraging its warmth-to-weight ratio
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  • Blending: When blended with other fibers, bison down can enhance the thermal properties of the resulting yarn while improving durability
    .

Additional Characteristics

Beyond its thermal properties, bison fiber offers other benefits that complement its insulating capabilities:
  • Softness: Despite its rugged origins, bison down is surprisingly soft, making it comfortable for direct skin contact
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  • Durability: Bison fiber exhibits high tenacity (8.7 cN/tex) and good extension (39.3%), contributing to the longevity of garments made from this material
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In conclusion, American bison fiber's thermal properties make it a unique and highly effective material for cold-weather applications, combining exceptional insulation with natural temperature regulation and durability.

American Bison Fiber truly makes the best socks and accessories. Our socks offer the best insulation, moisture wicking, and odor control. To create the most comfortable and easy care sock possible, we blend American Bison Fiber with other high quality fibers.  We currently have 8 different styles of socks, for various footwear types, climates and activities, and while they are all somewhat different, there are some properties that apply to all.

Advantage Trekker Bison/Merino Boot Socks Bison Footwear The Buffalo Wool Co.
Why do we blend Fibers?

In all our socks, we blend ultra soft American Bison fiber with a variety of other fibers to supplement construction. This is an important note - these fiber blends are critical to creating a sock that works (and plays) as hard as you. These fibers make our socks flexible and durable, and more comfortable. We decide on the “Base Yarn” composition and then send it to the sock mill. There they use additional yarns and threads to complete the sock.

The internal sock structure (all the sock parts that touch your skin)  are, and will always be, natural fibers, usually bison fiber, merino wool or mulberry silk.  The construction components are used to make the sock more durable and reinforce wear areas to give the sock some extra durability.  Our primary reinforcing material is nylon; we use this fiber to reinforce the outside heel and ankle area of our socks, but the inside layer (the part that cradles your foot) remains American Bison Fiber.

What other Fiber do you use?

Most commonly, we use blends of merino wool, bamboo, silk, nylon, and polyester. The helpful chart below details our sock composition and common blends.

One of the core foundations of The Buffalo Wool Co. is creating amazing American Bison products made from USA sourced materials. Our fiber blends are no exception. Our Merino Wool is sourced here in the US from Colorado and our nylon is from North Carolina. We take great pride in the fact that we only import our silk and bamboo fibers - and that’s because no silk or bamboo fibers are grown domestically. Many of our socks are also Berry Compliant as we proudly serve the U.S. Military.

The Best Socks - Guaranteed

Our American Bison Fiber Socks are as soft as cashmere and as tough as nails - all because we use the best fiber for the job. American Bison Fiber ensures your feet are insulated no matter the weather or water, while other fibers give you top notch flexibility, durability, and easy care.

There really is a Bison Fiber Sock for everyone, and we know you’ll love them. Guaranteed.

Our World-Famous Bison Fiber Socks

Advantage Trekker Bison/Merino Boot Socks Bison Footwear The Buffalo Wool Co. Medium 1 Pair Pro-Gear Technical Boot Bison/Silk Socks Bison Footwear The Buffalo Wool Co. Medium Yellowstone Bison/Merino Crew Socks Bison Footwear The Buffalo Wool Co. Pro Gear Crew Socks Red Dog Kids American Field Jr. - Crew Socks Casual Crew 2.0 Bison/Bamboo/Merino Bison Footwear The Buffalo Wool Co. Medium One Pair The B.O.S.S. (Best Overall Short Sock) Bison Footwear The Buffalo Wool Co. Natural Medium O.T.C. - Advantage Gear Compression Sock Kenai - Ultralight Gear Boot Sock O.T.C. - Advantage Gear Compression Sock - Seconds Yellowstone Bison/Merino Crew Socks Bison Footwear The Buffalo Wool Co. Kenai - Ultralight Gear Boot Sock- seconds Casual Crew 2.0 Bison/Bamboo/Merino Bison Footwear The Buffalo Wool Co. Medium One Pair Advantage Trekker Bison/Merino Boot Socks Bison Footwear The Buffalo Wool Co. Medium 1 Pair
Trekker - Advantage Gear Boot Socks Pro Gear Boot Socks Yellowstone - Advantage Gear Crew Sock Pro Gear Crew Socks Red Dog Kids American Field Jr. - Crew Socks Casual Crew 2.0 - Ultralight Gear Crew Socks The B.O.S.S. - Ultralight Gear Short Sock O.T.C. - Advantage Gear Compression Sock Kenai - Ultralight Gear Boot Sock O.T.C. - Advantage Gear Compression Sock - Seconds Yellowstone - Advantage Gear Crew Sock Seconds Kenai - Ultralight Gear Boot Sock- seconds Casual Crew 2.0 - Ultralight Gear Crew Seconds Trekker - Advantage Gear Boot Socks- seconds
Performance Blend Advantage Gear Pro Gear Advantage Gear Pro Gear Ultralight Gear Ultralight Gear Ultralight Gear Advantage Gear Ultralight Gear Advantage Gear Advantage Gear Ultralight Gear Ultralight Gear Advantage Gear
Base Yarn 50% American bison down / 50% Merino wool 50% American bison down / 50% Silk 50% American bison down / 50% Merino wool 50% American bison down / 50% Silk 33% American bison down / 33% Merino wool / 33% Bamboo 34% American bison down / 33% Merino wool / 33% Bamboo 34% American bison down / 33% Merino wool / 33% Bamboo 50% American bison down / 50% Merino wool 34% Bison Down / 33% Ultrafine Merino Wool / 33% bamboo fiber 50% American bison down / 50% Merino wool 50% American bison down / 50% Merino wool 34% Bison Down / 33% Ultrafine Merino Wool / 33% bamboo fiber 34% American bison down / 33% Merino wool / 33% Bamboo 50% American bison down / 50% Merino wool
Overall Composition 38% merino wool / 30% American bison down / 30% nylon / 2% Lycra spandex 32% American bison down / 32% silk / 26% nylon / 4% polyester / 4% Tencel / 2% Lycra spandex 36% Merino wool / 28% Bison down / 26% Nylon / 8% Polyester / 2% Spandex 30% American bison down / 30% silk / 30% nylon / 4% Tencel / 4% polyester / 2% Lycra spandex 24% American Bison Down / 24% Merino Wool / 23% Bamboo Fiber / 23% Nylon 4% Poly / 2% Spandex 26% American bison down / 25% merino wool / 25% bamboo / 20% nylon / 3% Lycra spandex / 2% polyester 24% American bison down / 24% merino wool / 24% bamboo / 23% nylon / 3% polyester / 2% Lycra spandex 45% merino wool / 31% nylon / 18% American bison down / 4% polyester / 2% Lycra spandex FOOT: 29% American bison down / 28% nylon / 25% bamboo / 16% merino wool / 2% Spandex | LEG: 72% polypropylene / 26% nylon / 2% Spandex 45% merino wool / 31% nylon / 18% American bison down / 4% polyester / 2% Lycra spandex 36% Merino wool / 28% Bison down / 26% Nylon / 8% Polyester / 2% Spandex FOOT: 29% American bison down / 28% nylon / 25% bamboo / 16% merino wool / 2% Spandex | LEG: 72% polypropylene / 26% nylon / 2% Spandex 26% American bison down / 25% merino wool / 25% bamboo / 20% nylon / 3% Lycra spandex / 2% polyester 38% merino wool / 30% American bison down / 30% nylon / 2% Lycra spandex
Customer Reviews

Our Bison Fiber Gloves

Extreme Gear Bison Gloves Extreme Gear Fingerless Gloves Bison Leather Gloves Combo glove set; Bison liner glove with deerskin over glove Liner Gloves
Extreme Gear Bison Gloves Extreme Gear Fingerless Gloves Bison Leather Gloves Leather Gloves and Liner Combo set Liner Gloves
Performance Blend Extreme Gear Extreme Gear
Base Yarn 90% American bison down / 10% Nylon 90% American bison down / 10% Nylon
Overall Composition
Customer Reviews

Our Bison Fiber Beanies, Balaclavas, and Knit Hats

Bison Beanie Bison Gear The Buffalo Wool Co. Ribbed - Brown Cabled Bison/Silk Knitted Hat Bison Gear The Buffalo Wool Co. Charcoal Balaclava - full head mask Bison Gear The Buffalo Wool Co. Pro-gear; 50% bison 50% silk Headband - Cabled bison headgear Bison Gear The Buffalo Wool Co. Pro Gear 50% Bison 50% Silk - Natural Diamond cabled knitted hat - Bison & Muga Silk Bison Gear The Buffalo Wool Co. Slouched Bison Beanie Bison & Silk Ribbed Beanie Diamond cabled knitted messy bun hat - Bison & Silk Bison Gear The Buffalo Wool Co. Advantage Bison/Merino Beanie Really Really Nice Bison Beanie Bison Ultra light beanie natural or black Balaclava - full head mask Bison Gear The Buffalo Wool Co. Extreme gear; 90% bison 10% nylon Buffalo Wool Co cowl Joel Bison Toque Qiviuk Collection Red Dog Kids Lined Beanie Extreme Gear Ribbed Headband Extreme Gear Balaclava - Eyehole only, limited run MENA TOQUE Qiviuk Collection Scarf, glove & Hat set Ultralight Combo set; Ladies hat, glove and cowl
Ribbed Extreme Bison Beanie Cabled Bison Beanie Pro Gear Balaclava - Full Mask Cabled Bison Headband Diamond Cabled Beanie Slouched Bison Beanie Bison & Silk Ribbed Beanie Diamond Open Top Beanie Advantage Bison/Merino Beanie Really Really Nice Bison Beanie Ultralight Gear Bison Beanie Extreme Gear Balaclava - Full Mask Ultralight Slouchy Beanie Joel Bison Toque Qiviuk Collection Red Dog Kids Lined Beanie Extreme Gear Ribbed Headband Extreme Gear Balaclava - Eyehole only, limited run MENA TOQUE Qiviuk Collection Scarf, glove & Hat set Ultralight Combo set; Ladies hat, glove and cowl
Performance Blend Extreme Gear Pro Gear Pro Gear Pro Gear Pro Gear Pro Gear Pro Gear Pro Gear Advantage Gear Luxury Gear Ultralight Gear Extreme Gear Ultralight Gear Extreme Gear Extreme Gear Extreme Gear Ultralight Gear
Base Yarn 90% bison down / 10% nylon 50% American bison down / 50% Silk 50% bison down / 50% Silk 50% American bison down / 50% Silk 50% American bison down / 50% Muga Silk 50% American bison down / 50% Silk 50% American bison down / 50% Silk 50% American bison down / 50% Muga Silk 50% American bison down / 50% Wool 50% American bison down / 50% Italian spun ultra fine merino wool 34% American bison down / 33% Merino wool / 33% Bamboo 90% American bison down / 10% Nylon 33% Bison down 33% Merino Wool 33% Bamboo fiber 90% American bison down / 10% nylon 90% American bison down / 10% Nylon 90% American bison down / 10% Nylon 34% Bison fiber, 33% Merino and 33% Bamboo
Overall Composition
Customer Reviews