Podcast 95 | Natural Fibers in Outdoor Performance Apparel
Episode Sponsor
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.
Listen
Summary
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.

In this Episode:
What’s New at Backpacking Light?
- Check out our education offerings and special events on the brand-new Backpacking Light Calendar.
- Member Q&A – January 11, 2024
- BPL Basecamp Spring ’24 Cohort – beginning January 31st!
Featured Gear: Comparing the XTherm NXT and Nemo Tensor Extreme
| Therm-a-Rest NeoAir XTherm NXT | NEMO Tensor Extreme Conditions | |
|---|---|---|
| Size Standard - Reg Wide | Mummy | Rectangular |
| thickness | 3 in (7.6 cm) | 3.5 in (8.9 cm) |
| weight | 19 oz (255 g) | 22 oz (624 g) |
| packed size | 5 x 11 in (12.7 x 27.9 cm) | 4.5 x 10.5 in (11.4 x 26.7 cm) |
| top fabric | 30d nylon | 20d nylon |
| bottom fabric | 70d nylon | 20d nylon |
| cost | $259.95 | $259.95 |
| R | 7.3 | 8.5 |
| insulation | aluminized film | aluminized film |
| noise | noisy | quiet |
| warmth | "warmer?" | ? |
| stability | horizontal baffles | pseudo-square baffles |
| insulation construction | triangular 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
Q&A
- 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 podcast@backpackinglight.com.
Links, Mentions, and Related Content
- Gear Testing and Research: By the Numbers: What’s the Best Base Layer Fabric? Wool vs. Alpaca vs. Polyester
- Gear Testing and Research: Why is my Baselayer Soaked?
- Gear Testing and Research: Air permeability vs. moisture vapor transmission rate (MVTR): which one impacts moisture transport more in wind and rain jackets?
- Podcast: Episode 90 | Alpaca Wool Baselayers
Go Deeper with Backpacking Light
- Sign up for the Newsletter.
- Become a Backpacking Light Member.
- Follow us elsewhere on the web: YouTube | Instagram | Facebook
How to Subscribe
- Apple Podcasts | Spotify | RSS
More Episodes
Credits
- Executive Producer - Backpacking Light; Show Director and Host - Ryan Jordan; Producer - Chase Jordan; Theme music: Look for Me in the Mountains written by Chris Cunningham and Ryan Jordan, performed by Chris Cunningham (acoustic guitar, lead and harmony vocals, harmonica), Chad Langford (upright bass), and Tom Murphy (mandolin), produced by Basecamp Studios in Bozeman, Montana.
Feedback / Tips / Questions
- podcast@backpackinglight.com
More Backpacking Light
- Sign up for the Newsletter.
- Become a Backpacking Light Member.
- Follow us elsewhere on the web: YouTube | Instagram | Facebook
Disclosure
- Sponsorship Policy: Backpacking Light does not accept compensation or donated/discounted products in exchange for product mentions or placements in editorial coverage, including any 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.


Discussion
Become a member to post in the forums.
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.
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?
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.
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.
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.
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.
The perils of dog ownership and wearing fleece. Great Pyrenees mix.
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…
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.
Thanks for the added info!
I really want to like merino base layers, but in my experience trying to use merino base layers from both montbell and smart wool, they fall apart quick- in the case of my montbell merino shirt, I bought it for a 4-day ski touring trip and after the trip I had holes on both shoulders. The smart wool layers held up a bit better but still not well. I have some costco poly base layers that I used intermittently for 5 years and regularly for another 5 years after that, and are still going strong. It’s hard for me to justify the premium price of merino layers and the increased frequency I’d need to replace them. If I could trust natural base layers would last the same way polyester ones do, I’d probably be willing to pay a premium to stink less and wear less plastic.
Funny enough, the exception to this experience is socks. My merino socks seem to last a lot longer than polyester ones, though that may be because poly socks I own are cheap ones from target. Regardless, the comfort (and minimal smell!) of wool socks has been an obvious improvement over synthetics for me.
Late answer to Ryan’s original question: I wore wool for many years, sometimes cotton in Summer. For at least a decade I’ve been wearing synthetics. As discussed in other BPL articles, synthetics are objectively better at handling moisture.
That said, the natural fibers work well enough, and it’s mostly a matter of personal preference.
Brynje does add a smidgen of comfort in cool weather. I like it, although it doesn’t replace any other layers. I cannot figure out how people wear it in Summer, though. It adds warmth, no matter what I wear over it.
Synthetics for decades, starting with polypropylene over 40 years ago. Then moved to Capilene a few years later.
Around 15 years ago I switched to wool. And some merino/poly blends. Problem with these is they wear out too quickly. The blends worked better, but are hard to find. After five years of wearing out expensive merino, I went back to Capilene — better ROI — less junk going into landfills if that is a concern for people.
(above BPL Beartooth Merino Hoody in 2009). I really liked this, but it wore out fairly quickly.
Pretty rare for me to get a clammy feeling with Capilene, which is probably a mixture of my physiology (I don’t sweat as much as most people) and getting the right combination of layering to meet the conditions.
After some trail and error I settled on wool, or wool blends after my 2009 JMT hike. On that hike every body part touched by synthetic fabrics (upper body where my t-shirt sat, where the liner in my baggies touched, and my feet) broke out in a horrific heat rash. I can contain it with application of cortisone and antifungal creams, but with natural fabrics (wool, cotton, viscose, bamboo fabrics, etc.) it never develops.
Not sure why I needed to be 52 years before it started, but age evidently has something to do with it.
Anyway, wool and wool blends dry faster than the other natural fabrics and though they cost more and wear quicker the lack of rash and painful pustules make it well worth the spend.
Become a member to post in the forums.