Why We Chose Hemp

Walk into any outdoor gear shop and spend five minutes looking at the walls. Down jackets engineered to maintain warmth at -40°F (-40°C). Insulation systems with names like PrimaLoft and Polartec and Thinsulate. Expedition parkas tested in conditions that roughly four thousand Americans will ever actually encounter. The cold side of the temperature spectrum has been studied, iterated, and genuinely solved by some talented people over several decades.

Then find the hot weather section.

It's usually a few shelves near the back. Mostly polyester. Some polyester-cotton blends. Maybe a linen shirt that's been positioned as a lifestyle item rather than anything technical. This arrangement suggests that cold is the condition requiring serious engineering and heat is the condition you manage by wearing less of something. Cold demands a solution. Heat just becomes an afterthought.

The heat problem has different physics than the cold problem. Understanding why comes down to one fact about how the human body actually cools itself.

Evaporation. Specifically, evaporation at the point where skin and fabric meet. When sweat evaporates at that interface, it pulls thermal energy away from the body right where the cooling is most efficient. Each gram of sweat that evaporates removes roughly 580 calories of heat from your skin, a consequence of water's latent heat of vaporization at body temperature. In dry heat, a well-hydrated person can maintain stable core temperature through evaporation alone, even when the sun is cooking you from above and the ground is radiating heat back from below. We went deep on this in the Death Valley piece. The short version: evaporation is your primary defense in extreme heat, and it works best when the fabric against your skin gets out of its way.

Everything else followed from that.

Linen

Linen is good. Genuinely good. Made from flax, which people have been cultivating for clothing for thousands of years, it breathes well and releases moisture freely and feels cool against your skin in a way that takes synthetic fabrics enormous chemical effort to approximate. For office wear, for dinner somewhere warm, for a weekend in a city where the temperatures are climbing and you want to look like a person who has things figured out, linen is probably the right answer. We'd rather you wore linen than polyester in almost any context.

Where linen starts to fall short is under the specific demands of outdoor use. Repeated abrasion from pack straps, sustained contact with brush on trail, the general mechanical punishment of technical activity: linen degrades under those conditions faster than hemp. Its UV protection is decent but lower than what hemp's fiber structure provides inherently. Its natural antimicrobial properties are real but weaker, which starts to matter on day three of a trip when you haven't been near a washing machine. For the office, linen is frankly better suited than hemp. For a week in canyon country with a pack on, hemp holds up where linen starts to show its limits.

Merino Wool

Merino wool is one of the most sophisticated natural fibers anyone has figured out how to make into clothing, and we mean that without any agenda behind it. Its ability to regulate temperature across a wide range is remarkable. It wicks, it resists odor, it handles the complicated push and pull of moisture and temperature across conditions that would make most fabrics give up. If you're in the mountains where the temperature swings 40°F (22°C) between sunrise and afternoon, or you're moving through variable weather across multiple days, you should have some merino layers with you. Truly. I have multiple and I love them. Merino and hemp are complements, not competitors.

The limitation with merino wool is specific to the top of the heat curve. Above roughly 90°F (32°C), the same structure that makes merino a good insulator starts to trap heat. Wool was shaped by evolution to keep animals warm. At 110°F (43°C), you don't exactly need to trap heat. But for reals, below 50°F (10°C), in cold water, in winter mountains, in anything where you need to retain warmth rather than shed it, choose wool without a second thought. Our gear is not meant for these conditions.

Cotton

Cotton is more complicated, and getting it wrong would mean being unfair to a lot of people who've been using it intelligently for a very long time.

A long-sleeve cotton shirt, soaked in water, is one of the most effective cooling garments you can wear in dry heat. Cotton absorbs and holds water exceptionally well, and as that water evaporates from the saturated fabric it pulls heat away from your body in a continuous process. Agricultural workers & construction crews alike already know this. A wet cotton shirt at 105°F (41°C) in low humidity is a real cooling tool. That's worth acknowledging plainly.

The problem is that cotton still doesn't perform as well as hemp. Cotton holds water well, which is the whole point, but that also means it stays heavy and wet for a long time. As temperatures push past 110°F (43°C), the water in a saturated shirt evaporates faster than you can practically replenish it, and once it dries out cotton doesn't have much left to offer. In humid conditions the situation reverses entirely: the fabric absorbs moisture it can't release into already-saturated air and you end up wearing a damp, heavy layer that's stopped cooling you and started trapping heat. Cotton's UV protection in its dry state is also limited compared to our fabrics, and it wears down faster than hemp under sustained technical use.

For casual warm weather and for the specific case of a soaked layer in accessible dry heat, cotton makes sense. For sustained performance across conditions that shift, it's not designed for the job.

Bamboo

Our earliest prototypes for the White Sands Hooded Henley were bamboo fabric. The pitch for bamboo is appealing on paper: soft, moisture-wicking, naturally derived, reasonable breathability numbers. The first samples felt good. So we started field testing them under load, meaning with a weighted backpack. Within a few miles the fabric was pilling badly wherever the pack straps made contact with the shoulders. We adjusted the construction and ran the test again. Same result. Bamboo's fiber structure doesn't hold up to the mechanical stress of actual outdoor use. It's a fine fabric for a lot of things. A garment you're putting under a pack in 100°F (38°C) heat on a canyon trail is not one of them. We put the prototypes in a box and started over.

Polyester

Polyester is straight-up awful.

It's a petroleum derivative, and that's only the beginning of the problems with it. Polyester does move moisture from skin to fabric surface faster than cotton, which the outdoor industry spent decades calling an advantage, and in cold-weather layering systems where the goal is to move moisture away from skin toward an outer layer, it genuinely is. But in heat the mechanism inverts. Polyester moves moisture to its surface and stops there. The fabric has no natural breathability. The space between polyester and skin fills with hot moisture the fiber can't absorb or release into the air efficiently. You are wearing a thermal barrier in the conditions where a thermal barrier is the worst possible thing to be wearing. The feeling is accurate: it feels like a plastic bag because the physics isn't far off from a plastic bag.

Polyester also can't do the things the hang tag says it can do on its own. Its fiber structure provides almost no UV protection and its synthetic surface traps odor-causing bacteria in ways that washing doesn't fully fix. The industry's answer to both of these problems is chemical treatments: antimicrobial sprays, UV-blocking coatings applied to the finished fabric. These work when the garment is new. They wash out. Most of these treatments degrade significantly within 10 wash cycles, sometimes fewer depending on water temperature and detergent. The hang tag describes a new garment under perfect circumstances. After a season of regular use you're wearing a petroleum-based thermal barrier that smells and sunburns you.

Then there's the microplastics issue. Research from the Bren School of Environmental Science at UC Santa Barbara, done in partnership with Patagonia, found that a single synthetic fleece jacket can shed more than 250,000 microplastic fibers in a single wash, particles small enough to pass through wastewater treatment and enter waterways. Subsequent research has found these particles accumulating in marine organisms and, more recently, in human tissue. Recycled polyester is made from reclaimed plastic bottles rather than virgin petroleum, which is a real improvement in how the material is sourced. It still sheds the same microplastic fibers into the same waterways with every wash. The recycled label addresses where the raw material came from. It doesn't address what the garment does for the rest of its life.

Polyester dominates outdoor apparel because it's cheap. That's the whole story. 

Hemp

Which, after all the aforementioned fabrics, we arrived at hemp. 

Shoutout to one of my best friends Joel who's an outdoor gear expert to get me to seriously look into hemp in the first place. It's a niche fabric, but it releases moisture into the air faster than cotton under most conditions and faster than polyester in low humidity. Its natural fiber structure moves moisture outward rather than holding it at the fabric surface. In arid conditions specifically, plenty of peer-reviewed research shows that fabric evaporative performance for natural fibers with open fiber structures seriously outperforms synthetic "moisture-wicking" fabrics on cooling efficiency.

Hemp's antimicrobial properties and UV protection come from the fiber itself, not from a chemical treatment applied afterward. Our garments achieve UPF 50+ through the combination of hemp's natural fiber properties and weave density. That rating doesn't wash out because it isn't a coating. It's the fabric. Hemp also strengthens and softens with repeated washing and wearing, which means the garment actually gets better with use rather than degrading. It held up through the same pack abrasion testing that eliminated bamboo without any meaningful surface breakdown.

Where hemp falls short, we'll say plainly. It's not good for water submersion. Hemp absorbs water readily, which is a feature in dry heat and a liability when you're repeatedly in and out of a river or the surf. A soaked hemp garment is heavy, slow to dry, and not doing anything useful for your comfort in those conditions. For water activities, synthetic fabrics or wool are better tools. We don't make gear for water submersion.

Hemp is also not a winter fabric. Below roughly 50°F (10°C), the breathability and moisture-releasing properties that make it work in heat start releasing warmth you need to keep. For cold weather, choose wool. There're lots of amazing outdoor brands that have done incredible stuff with wool. 

For humid conditions, pure hemp has a ceiling even within its intended range. When the air is already saturated, evaporation slows regardless of what you're wearing, and what helps is distributing moisture across as much fabric surface area as possible. We originally didn't want to do any short-sleeves, but for humidity, we found short-sleeves dissipate heat in the humidity the best (hence the origin of our Everglades, the short-sleeve variant of our Canyonlands shirt). 

The Canyonlands Long-Sleeve, Everglades Short-Sleeve, and Joshua Tree Trail Pants are 100% woven hemp (with the White Sands hooded henley featuring a 55% hemp 45% tencel knit blend), built for heat in which hemp's evaporative efficiency is at its best. The ventilation in the button-up shirts are positioned where the body traps heat the most, and the cut creates airflow around the areas where heat and sweat typically accumulate.

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Hemp is one of the oldest cultivated plants on earth. Linen has been keeping people cool in hot climates for millennia. Outdoor workers figured out the wet cotton principle long before anyone published research on evaporative cooling efficiency. None of what we're doing is new in that sense. What's different is the question we started with: what does the physics of human cooling in extreme heat actually require from a fabric, and what's the most honest answer to that question? The bamboo prototypes in the box are a useful reminder that the answer we arrived at wasn't the first one we tried.

The cold problem got solved. We're solving the heat problem.