Podcast Episode January 8, 2024

Podcast 95 | Natural Fibers in Outdoor Performance Apparel

Episode Sponsor

a computer generated image of a man in a suit and tie

This episode of the backpacking light podcast is sponsored by ARMS OF ANDES, manufacturer of premium base layer apparel made with alpaca wool. Backpacking Light podcast listeners can enjoy 15% off with the coupon code ALPACALIGHT at armsofandes.com.



In episode 95 of the Backpacking Light podcast we’re going to learn about the types of natural fibers that make up the fabrics we use for base layer and insulating apparel.

a couple of animals that are in the grass

In this Episode:

What’s New at Backpacking Light?

Featured Gear: Comparing the XTherm NXT and Nemo Tensor Extreme

Therm-a-Rest NeoAir XTherm NXTNEMO Tensor Extreme Conditions
Size Standard - Reg WideMummyRectangular
thickness3 in (7.6 cm)3.5 in (8.9 cm)
weight19 oz (255 g)22 oz (624 g)
packed size5 x 11 in (12.7 x 27.9 cm)4.5 x 10.5 in (11.4 x 26.7 cm)
top fabric30d nylon20d nylon
bottom fabric70d nylon20d nylon
insulationaluminized filmaluminized film
stabilityhorizontal bafflespseudo-square baffles
insulation constructiontriangular baffles made with reflective surfaces (isolate air movement)horizontal aluminized surfaces that allow for convective air movement up and down the length of the pad

Main Topic: Fundamentals of Natural Fibers

  • The primary differences between natural fibers and synthetic fibers – source, moisture management, thermal properties, durability, comfort and feel, odor resistance, environmental impact, care and maintenance, cost
  • New research on aerogel fabrics
  • Types of natural fibers:
    • Plant-based fibers – cotton, linen / flax, hemp, jute, bamboo, sisal
    • Animal-based fibers – wool, silk, cashmere, mohair, alpaca, mohair, angora
    • Mineral-based fibers – asbestos
  • Comparing the structure of plant-based and animal-based fibers – cellulose vs protein structures, microscopic structure, absorbency vs thermal properties
  • Unique characteristics of wool fibers – crimp, keratin-based, hygroscopic nature, thermal insulation, odor resistance, flame resistance, biodegradability, felting, dyeability, elasticity and comfort
  • Merino Sheep Wool vs Other Kinds of Wool – fiber diameter and fineness, crimp, strength and durability, comfort and feel, breathability and moisture management, odor resistance, price, and availability
  • Merino sheep wool vs Alpaca Wool – fiber texture and softness, warmth and insulation, weight, moisture wicking and breathability, hypoallergenic properties, durability and elasticity, odor resistance, price and availability, environmental impact
  • Comparing and Contrasting Huacaya Alpaca Wool and Suri Alpaca Wool


  • What’s the best baselayer that works with a waterproof-nonbreathable jacket like those from Lightheart Gear and Antigravity Gear?
  • What’s the difference between fishnet baselayers from Brynje and those from Wiggy’s and others?
  • Can fishnet be used in warmer temperatures?

Submit a Tip, Trick, or Question

Share your tips, tricks, and questions on the podcast – submit it via email to [email protected].

Links, Mentions, and Related Content

Go Deeper with Backpacking Light

About the Backpacking Light Podcast


More Episodes

Feedback, Questions, Tips?


  • Backpacking Light - Executive Producer
  • Ryan Jordan - Director and Host
  • Chase Jordan - Producer
  • Look for Me in the Mountains - Music


  • This episode of the Backpacking Light Podcast is supported and kept advertising-free by Backpacking Light membership fees. Please consider becoming a member which helps support projects like this podcast, in addition to a whole slew of other benefits!


You can contact us at [email protected], or follow us on social media -


(Updated April 9, 2024)

  • Product mentions: Backpacking Light does not accept compensation or donated/discounted products in exchange for product mentions or placements in editorial coverage, including podcast episode content not excplicitly identified as sponsored content.
  • Some (but not all) of the links in these show notes may be affiliate links. If you click on one of these links and visit one of our affiliate partners (usually a retailer site), and subsequently place an order with that retailer, we receive a commission on your entire order, which varies between 3% and 15% of the purchase price. Affiliate commissions represent less than 15% of Backpacking Light's gross revenue. More than 70% of our revenue comes from Membership Fees. So if you'd really like to support our work, don't buy gear you don't need - support our consumer advocacy work and become a Member instead.
  • Learn more about affiliate commissions, influencer marketing, and our consumer advocacy work by reading our article Stop wasting money on gear.
Free Handbook

Get ultralight backpacking skills, gear info, philosophy, news, and more.

Home Forums Podcast 95 | Natural Fibers in Outdoor Performance Apparel

Viewing 10 posts - 1 through 10 (of 10 total)
  • Author
  • #3801086
    Backpacking Light


    Locale: Rocky Mountains

    Companion forum thread to: Podcast 95 | Natural Fibers in Outdoor Performance Apparel

    In episode 95 of the Backpacking Light podcast we’re going to learn about the types of natural fibers that make up the fabrics we use for base layer and insulating apparel.

    Ryan Jordan


    Locale: Central Rockies

    Ten years ago, I mostly opted for wool because it was so good at resisting odors (still is). Synthetics have gotten much better for long-term wear since about 2018, but still have a ways to go. I’m still not a fan of wearing clammy base layers, so I still lean towards wool (often with a fishnet layer underneath). Has anyone else been wearing wool historically and gone back to synthetics? Or vice-versa?

    BPL Member


    Locale: The West is (still) the Best

    Doing some research (reading) for a just completed merino wool purchase, the knock on merino is still durability especially under pack straps according to the reviews. Another fairly new company has their merino a little thicker, but will it start affecting hot weather hiking temperature? Probably individual.. Some articles (mostly climber based) point out that merino still holds water vs synthetics, but most “merino” are blends.

    Still feel the durability especially where a pack abrades against fabric should be addressed (but it won’t be).

    I plan on using my second merino as a sleeping shirt to take advantage of its comfort range and only use for hiking in case of emergency.
    Also just ordered some merino socks from a well-known company  and while socks must have nylon, it seems the nylon content is slowly going up %-wise.

    David D
    BPL Member


    Wool doesn’t feel clammy but when I stop and its very cold, I feel like I’m wearing a comfy but dangerous sponge.  For me, it holds too much water.

    I’ve switched to Brynje mesh under tight fitting Lifa.  It manages sweat much better (allows it to escape) and the tightfitting Lifa adds a lot of warmth with the air trapped in the mesh.  Stopping doesn’t feel as dangerous and my skin doesn’t feel as cold after a long winter day hike.   Drawback is wind cuts right through the combo easier.  I might add a cheap Dooy for when the wind is howling.

    Terran Terran
    BPL Member


    I usually wear a layer of Great Pyrenees over any wool or fleece., I read it can be 80% warmer than sheep’s wool. I prefer the alpaca wool. I’ve been wearing bison wool socks for a few years. I have some (unfortunately discontinued) thin wool/silk blend socks for warm weather, otherwise I prefer synthetic.. I like a thin layer of wool for warmth. I can shrink it for a better fit. Synthetic fleece over that to deal with the elements better and to add loft to a hard shell.

    Bill Budney
    BPL Member


    Locale: Central NYS

    I usually wear a layer of Great Pyrenees over any wool or fleece

    I can’t figure out whether that is a joke, a typo, or a name brand that I haven’t heard of.

    Slightly unsure that I want to ask.

    Terran Terran
    BPL Member


    The perils of dog ownership and wearing fleece. Great Pyrenees mix.

    Mark Ferwerda
    BPL Member


    Locale: Maryland

    I Just finished listening to this podcast. Regarding the environmental impact by sheep, I always thought the biggest impact by sheep was that they tend to strip the land of vegetation by nibbling down to the roots.  I thought that was why the cattle ranches of the 1800s hated sheep so much. Cattle did not overgraze like sheep did…

    Terran Terran
    BPL Member


    Cattle can overgraze as well if allowed to. You end up with an accumulation of parasites that affect cattle but the sheep can handle them. Sheep can go in where cattle have grazed. The pasture can be then overgrazed or cleared depending on how you look at it. While the cattlemen were following best practices and rotating fields, the sheepherders, who were a bit more desperate, would take advantage of the fallow pastures, thus giving sheep a bad reputation.

    Mark Ferwerda
    BPL Member


    Locale: Maryland

    Thanks for the added info!

Viewing 10 posts - 1 through 10 (of 10 total)
  • You must be logged in to reply to this topic.

Join Our Community

Become a Backpacking Light Member

Forum Access

Unrestricted access to all forums, plus the ability to post and start new threads.

Premium Content

Unrestricted access to all 2,300+ articles, gear reviews, skills, stories, and more.

Community Posts

Post new content to the community including gear swaps, reviews, trip reports and more!

Online Education

Get unlimited access to all our online education (*Unlimited membership required).

Pack less. Be more. Become a member today!

Get Started