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Looking to upgrade your wardrobe? Check out our favorite merino wool shirts for summer and fall hiking, biking, and more.
Merino wool is a pretty magical fabric. It’s lightweight, it wicks away moisture and odors, and it helps thermoregulate (that is, it’s breathable). When it comes to outdoor wear, it’s dang near tough to beat.
That being said, there are some tradeoffs for this wonder textile. It can be more fragile and less durable, both in wearing and washing, which is why we considered both 100% merino wool layers and merino wool blends (with a majority of merino greater than 60%).
It’s not easy to find that perfect, comfortable yet functional, fits-great, do-it-all layer, but merino comes pretty darn close.
We tested dozens of merino wool shirts to find the best on the market, wearing them in all kinds of conditions and pushing the shirt’s limits. Here are our staff’s favorite merino tees — as well as some honorable mentions.
At the end of our selection, check out our in-depth buyer’s guide, comparison chart, and frequently asked questions section to guide you to your next wear-all-day shirt.
Editor’s Note: We updated this guide on September 8, 2023 with two new worthy merino wool shirts: the Ridge Merino Solstice Lightweight Pullover Hoodie and Minus33 Ossipee/Chocorua Crew, and added additional information on our testing processes and sustainable wool sourcing.
Our staff testers love the Tech Lite II Crewe T-Shirt ($80) by icebreaker because we can wear it all year. In hot weather, this tee is light, breathable, airy, and made of 100% natural merino that has built-in odor-wicking properties. In cooler weather, it feels soft and comfortable as a base layer.
For a tee that can be used in any type of weather, it was easy for us to consider the Tech Lite II as the best merino wool shirt overall.
While comparing this tee to others that we had tested, we did feel that the Tech Lite II felt slightly thinner than other tees, which made us wary about its durability. However, after a few years worth of testing now, we’re comfortable with the quality and longevity.
Overall, we are impressed by the amount of use we get from this tee, regardless of the weather. We also really love the fit and coverage, especially the sleeve length on the women’s cut. While the Tech Lite II Crewe is a bit thinner for the price, the outstanding quality makes it a great buy.
Testing the Patagonia Capilene Cool Merino Shirt ($69) exceeded our expectations, especially for the price. This shirt is a blend of 65% RWS-certified merino wool and 35% polyester, which kept us cool — as the name suggests — while hiking in balmy summer temperatures. Yet when we added another layer, it kept us comfortable when the air got chilly.
Another thing we appreciated about this shirt is how lightweight, airy, and not quite as sheer it is as other merino tops — an easy standalone top for various activities. Additionally, after wearing it all day and underneath a pack while backpacking, it stayed surprisingly odor-free. In fact, it easily made it on our list of go-tos for multiple-day excursions.
Unfortunately, this top isn’t perfect. We found signs of pilling and snags after a couple of washes. However, given its reasonable price and the fact it requires fewer washes in between wears, we still like it. And since it has a sizable percentage of polyester, it’s not exactly as soft as other 100% merino shirts, but still, we think it’s pretty soft considering.
If you want a shirt that fits comfortably, doesn’t impede mobility, is versatile in both cool and warmer temperatures, and is reasonably priced, then the Capilene Cool Merino Shirt is a strong contender, in our opinion.
Vermont-founded Ibex has been making merino apparel since 1997. After a short out-of-business stint (that then lasted 2 years), the Ibex brand is finally back. We’ve been testing a number of styles, including this 24-Hour Short Sleeve Tee ($88), which is made with 100% 19.5-micron merino wool and is just as soft and light as it sounds.
What we appreciated most about this tee: It regulates the body’s temperature in hot weather, is moisture- and odor-wicking, and is lightweight. Additionally, it feels nice against the skin, works as a standalone tee or base layer, and it’s easy to hand wash and hang dry, which is perfect for travel.
Our main warning with this tee is that it is more fitted than others. So, if you want a roomier fit or if you are in between sizes, be sure to size up.
If you want a tee that breathes, the 24-Hour Short Sleeve Tee is it. Synthetic performs by the numbers, but the feel of natural materials — merino wool in particular — is unparalleled. And no one does merino better than Ibex, so it’s great to see the brand in full swing!
And heads up: this Ibex merino tee comes in a tank (even lighter with 18.5-micron wool) and long-sleeve versions as well, giving you more options for style and fit.
Light and airy — that’s almost everything you need to know about the Allbirds Natural Run Tee ($58), though we should also mention the sustainability factor: this tee is made of a mix of eucalyptus tree fiber and merino wool, so you can feel good about what you wear.
Made of an ultra-breathable mesh weave, this tee was made to run. We especially appreciated the anti-chafe seams and sneaky drop pocket on the hem of the shirt, perfect for stowing keys or cards. During a few test trail runs, the Natural Run regulated temps wonderfully during a chilly fall day that turned warm by afternoon.
Because it is a rather thin weave, you’ll have to be careful not to snag it on anything — something we weren’t capable of. The shirt held up well, but we could imagine a failure in the worst-case scenario. Speaking of the sheer fabric, it isn’t going to be for everyone, as you can see through it against direct light.
Perfect for a day of running where you aren’t sure what the weather has in store for you, the Allbirds Natural Run Tee ticks all the boxes we look for in an active-wear running merino shirt.
One of the downsides of the plushness of merino wool is its fragile nature — not something that’ll fly when scrubbing around in the brush. Thankfully the KUIU ULTRA Merino 120 LT SS Crew-T ($79) makes use of a new fabric tech that pushes the strength of merino to new heights and makes it perfect for your next hunting trip.
Nuyarn takes the soft touch of merino wool and spins it around a nylon core, greatly increasing its durability and stability. And since the fiber is drafted as opposed to twisted, it retains all of the high-loft softness and breathability we love about merino.
We loved the feel of the ULTRA Merino 120 LT SS in hand, and during use, it felt like a fabric we wouldn’t be worried about moving around in the woods with. KUIU claims its fabric has a 35% increase in stretch over normal merino, and we believe it.
Currently, there isn’t a women’s version of the ULTRA Merino 120 tee — the closest you’ll get is the Women’s ULTRA Merino 145 LS Crew ($79), a version with a thicker 145 g/m² fabric weight. We would love to see the thinner and more breathable fabric of this tee brought to the entire lineup.
Since the temperature-regulating qualities of merino are allowed to shine through, the KUIU ULTRA Merino 120 LT SS Crew-T would make a perfect tee for anyone looking for a standalone hot-weather or base-layer cold-weather hunting shirt.
Unbound Merino says “We want you to pack and own less,” and their Merino Crew Neck T-Shirts ($88) make that vision possible. With a classic cut, versatile color pallet, and no visible logos, the 100% merino tee is the ideal travel shirt.
Our tester wore this top for five days straight while hiking, climbing, running, and going out for drinks. Even after working up a sweat several times in the sun, the Merino Crew Neck held very little odor, especially when compared to a cotton tee. We were also impressed by the wrinkle resistance after days of use. The 17.5-micron merino is so comfortable that our tester fell asleep in this shirt several times and just continued wearing it the next day.
We also appreciate Unbound’s commitment to ethical production alongside quality, with wool sourced from mulesing-free wool farms in Australia. Mulesing is a controversial practice that removes skin from a sheep’s backside to prevent parasitic infections. Unbound’s production facilities are also WRAP (Worldwide Responsible Accredited Production) certified, and their merino is Woolmark certified.
Unbound warns to “never tumble dry” this top, making it a little more high maintenance than some merino shirts. Though with its excellent odor resistance, you’ll rarely have to wash it. With its simple design, it can easily transition from sightseeing or hiking to an evening out. If you want to pack a single t-shirt for a week-long trip, look no further than the Unbound Merino Crew Neck.
Our Senior Editor Nick Belcaster donned the Ridge Merino Solstice Lightweight Pullover Hoodie ($85) for a romp on Iceland’s Laugavegur Trail this summer and came away sold. Long an adherent to using sun hoodies for hiking, this was the first merino wool cut he had tried, and reported “killer breathability, quick drying, and just a nice loose drape to the fit.”
Made with a 17.5-micron merino wool that’s been blended with 13% nylon for strength, the Solstice hits about the perfect ratio in our books when it comes to adding a little durability to the merino garment, without totally diluting the natural properties you’re looking to hold onto. Ridge Merino’s wool comes from the land of the long white cloud, and is sourced from Kiwis in the McKenzie Basin.
While sun protection typically isn’t a priority for hikes across Iceland’s highlands, our testing with this hoody yielded an out-of-character three full days of UV, and we were pleased to be able to tuck away under the voluminous hood.
The sleeves on the Solstice are also cut a bit on the longer end, and are finished off with low-profile thumb loops to keep the sleeve ends over the backs of your hands. Even breaking a sweat couldn’t overwhelm the Solstice, which moved moisture out of the hoody and kept the funk off us after the full 35 miles.
Alas, everything has a limit, and the end of our hike was marked by a small wear hole in the right sleeve. Not surprising after three days of hard use, but it goes to show that merino will need to be treated with extra care to ensure that it goes the distance. We put the estimated life span of this hoody at one good thru-hike — which for most folks will be plenty long. Our testing will continue with it until we find the true end of this hoody.
For those looking for the ultimate sun protection top that doesn’t inhibit breathability, the Ridge Merino Solstice sun hoody provides full coverage in a premium merino weave.
Smartwool doesn’t make just socks; it makes all sorts of apparel, like the Merino Short Sleeve Tee ($80). This moisture-wicking tee kept us cool on warmer-weather hikes but also offered good coverage.
This layer is a super-comfortable piece at a reasonable price and is now more sustainably made. In terms of construction, we like that it is made with 87% merino with a nylon-spun core, striking a good balance between soft, stretchy, breathable, and durable.
We also like that the layer was durable when packed, worn, and washed multiple times over the few months we tested. This tee has a lot to offer while still being reasonably priced, making it a great option for those who want a budget-friendly tee.
Despite loving that this tee runs taller for those with a longer torso, we did discover that the sizing for different body types was a bit trickier than other merino tees we’ve tested — possibly due to some versions of the tee being colored with plant-based dye.
However, after finding the right fit, we actually enjoyed the options of plant-based colors, which make this tee a unique departure from the standard black or gray hues we usually see in merino layers. And who doesn’t love tie-dye?
If you want to keep on the go while still remaining stylish, look no further than the Smartwool Merino Short Sleeve Tee.
When the temperature starts to drop, you’ll stay cozy in this 100% merino long-sleeved crew. With a knit of 235 g/m2, this top is a bit heavier than others on this list, making it a great option for cooler weather. We mainly wore it as a low-profile mid-layer, but it could also be used as a base-layer during winter activities like skiing or snowshoeing.
The Minus33 Ossipee and Chocorua Crew ($80) is loosely fitted, making it easy to pull on over a light layer. Tester and climbing guide Katie Griffith brought it along on cloudy cragging days to stay warm while belaying, and also wore it hiking during a typical overcast and rainy June day in the Pacific Northwest. Overall a big fan of the Ossipee, Griffith did note that when the sun came out, she quickly became a bit too warm while active in this mid-weight top.
The 100% merino wool fabric is super soft against the skin; we forgot to take it off at night and ended up wearing it as a pajama top several times. The Ossipee crew can also join the rest of your laundry in the washer and dryer, making it a pretty low-maintenance wool piece.
When you’re moving fast during warmer weather, Minus33 recommends its micro or lightweight wool tops. But the Midweight Ossipee and Chocorua Crew are perfect for winter sports or activities like belaying or fishing that don’t require high output.
Like Smartwool, Bombas is another brand known for making high-quality socks — but they also craft other apparel, like the Merino Wool Crew Neck Long Sleeve T-Shirt ($74). Right off the bat, we loved the silky-soft feel of this tee, which felt like a plush pajama top.
That’s thanks to its 50% merino and 50% TENCEL Lyocell blend, which not only makes it feel incredibly comfortable but also aids in its ability to dry quickly when sweating or battling light precipitation.
It also contains cooling elements that are perfect for hiking in warmer temperatures. Other bonuses we admired were its UV protection properties and thumb holes for properly staying put underneath layers or under gloves.
Oh, and we can’t forget about the flattering colors this merino tee comes in — welcome additions to the otherwise standard black and gray merino shirts.
Unfortunately, we would be remiss if we didn’t discuss a few of the tee’s shortcomings. For starters, we weren’t thrilled that this midweight top is quite see-through, especially in the lighter colors. Since it claims to be made for layering, however, it’s not a problem with that in mind.
Another issue was its odd fit. We found it a bit tight in the arms and bust area and too loose everywhere else. If you’re finding the sizing too tight as we did, we suggest sizing up.
After taking a moment to select a size that works for you, you will be happy to have this ridiculously soft and warm Merino Wool Crew Neck Long Sleeve for your cold-weather hiking, biking, or camping adventures.
While other wools can be as coarse as 40 microns (think itchy grandma sweaters), merino wool can be as thin as 24 to 15 microns, which is exactly why the Ridge Merino Journey and Wander Merino Wool Shirts ($60) — made with 17.5-micron merino — are so dang buttery smooth.
Mammoth Lakes-based Ridge Merino certainly has a thing for good wool, having crafted an entire line revolving around sheep’s clothing. The Journey tee is easily one of its most popular, and we found it’s for good reason. This tee is just all-around cozy.
Sewn with a double-stitched neck and sleeves, the Journey felt like it was made for the long run in our testing. Couple that with the nylon core-spun merino textile, and you’ve got a durable merino piece that’ll keep up for as long as you’ll wear it. There’s also no external branding on this tee — which is something we’ve actually come to appreciate.
We particularly liked the cut of this tee, which is a bit slimmer and longer, though washing and drying will shrink the tee to some degree. This can cause a little confusion when trying to size the tee, but thankfully Ridge Merino provides a sizing chart to assist.
When comfort is king, the Ridge Merino Journey and Wander Merino Wool Shirts are high on our list of most cozy merino wool shirts.
The Voormi River Run Hoodie ($139) is made of 100% merino wool, but with a unique blend and construction. This USA-made hoodie uses an ultralight Precision Blended Wool, a fabric weighing under 100 g/m². That’s 30 to 50 grams lighter than the leading merino fabrics currently on the market, Voormi claims.
When packing and when wearing, we can attest that this hoodie is light. In fact, it’s so light and versatile that we’re not sure where we haven’t worn this Voormi layer — paddleboarding, camping, climbing, snowshoeing, kayaking, hiking, and running errands. And with the amount of time spent under the sun, the UPF 50-rated protection of this sun protection shirt is a welcome feature.
So what are our cons? It’s crazy ultralight and soft, meaning it’s prone to snag easily, which also doesn’t bode too well with the high cost. But ultimately, with the amount of wear this hoodie has gotten, it’s well worth the investment.
The River Run Hoodie was designed with everything from fly fishing day trips to multiday river trips in mind, which is one of the main reasons we love it so much. So, if you are heading up into alpine territory, or looking for a merino base layer for fall, it’s a good choice for that as well.
Folks at GearJunkie have been dyed-in-the-wool fans of merino since well, forever. Merino wool has been the premium activewear textile of choice for many GearJunkie testers, and we’ve used shirts made from the material for years. In order to find the best merino wool shirts, we raided our closets, pulled out our most trusted tops, and put them to work.
On top of that, we also surveyed the market for the latest and greatest merino wool options — finding new technologies like Nuyarn — and added them into the mix. Our search for the best merino wool shirts available today began with eight woolen tops in 2021, which we selected for their broad appeal and availability, and then set about wearing them threadbare in our search for the softest, most breathable, and hardiest merino wool shirts out there today.
In 2022, our horizons broadened when Senior Editor Nick Belcaster and contributor Rebecca Ross brought in a new slate of five additional merino wool shirts and added an award-winning choice for hunters. Our most recent testing saw merino wool shirts used across the planet, from the backs of professional climbing guides in the granite crags of the North Cascades to the world-famous Laugavegur Trail in Iceland. Our awards once again expanded to include a merino wool sun hoody, as well as a handful of other exceptional shirts from upstart companies focused solely on merino.
Our testers included outdoors folk from across the country, who hit the hills and trails decked out in merino in order to test fit, comfort, style, and durability. We paid special attention to finding layers that had a perfect balance of the softness of merino while still maintaining some strength over the long run. Our longest-running merino pieces now have three years of use on them, and we’ll continue to test them to learn more about their ultimate longevity.
Merino wool is a natural fiber that is grown by Merino sheep, which are thought to be the oldest breed of sheep in the world and have adapted to thrive in harsh environments, such as the highlands of New Zealand, Australia, and South America. Their wool is much finer and softer than other strong wool breeds, and when woven into garments provides a number of other benefits that we all can appreciate.
For one, merino wool has a unique scale-like structure that aids it in wicking moisture away from the skin — something that synthetic fibers aren’t great at. These structures are also the reason merino wool is so good at temperature regulation, with sweat being transported away when it’s hot, and insulating air being trapped next to skin when it’s cold.
Merino wool also isn’t bogged down by the typical funk of synthetic garments, and is amenable to being layered over top of due to its breathability. There are some tradeoffs, however, which come in the form of overall durability (full merino weaves can develop holes over time), and price. It isn’t cheap to produce hard-working fabrics, and you’ll certainly fork over the dough for the good stuff.
Merino wool comes from sheep, and since we want to treat our woolen friends with all of the respect they deserve, the vast majority of merino wool garment manufacturers are now demanding wool that has been produced in sustainable and ethical ways. One practice of concern has been mulesing, which removes skin from the hind end of sheep to limit infections, and has been banned in New Zealand. Thankfully, many manufacturers now guarantee their merino to come from mulesing-free farms.
Because of this demand for sustainable wool, a number of different non-profit entities offer certifications and audits of the merino wool supply chain. One such is the Woolmark Company, which is an Australian non-profit that tests merino wool to ensure quality, durability, and traceability. Another is the ZQ Program, which ensures that merino sheep under their certification are treated ethically, are never mulesed, and that the environment is taken into consideration at all steps of the fiber-production process.
Finally, the Responsible Wool Standard, or RWS, is another global certification that ensures that the entire supply chain from beginning to end upholds the tenets of animal welfare protection, land preservation, and working conditions, and is all audited by third-party certification bodies.
The decision to go full-merino or with a blend will be a personal preference. That said, there are certain things that 100% merino wool is hands-down good at. First, 100% merino wool provides a more next-to-skin feel than a merino blend, especially those that have a higher synthetic content. Second, merino wool offers natural antibacterial, UV protection, and moisture-wicking properties that synthetics don’t naturally have.
However, when it comes to a merino blend, there are certain beneficial features, such as tending to be cheaper and easily outlasting their more fragile counterparts. Simply: adding smaller percentages of synthetics can help to shore up the deficiencies of merino, without totally stripping out the benefits.
If you want a merino layer for hiking, hunting, or just spending time outside, consider all the uses 100% merino wool has to offer. And if you’re investing in a merino shirt for, say, a rugged backpacking trip or rock climbing, or if durability is of high importance, then go for a merino blend.
Also, if you are brand new to merino and just want to try it out and see what all the fuss is about, a merino blend can be a bit more wallet-friendly the first time around.
Polyester: Polyester is a manmade material that has much better dry times than merino wool and resists shrinking in the wash — something merino wool struggles with. A blend can offer a textile with components that complement each other so you end up with a garment that works for many situations.
Most merino wool shirts tend to use as high of a percentage of merino wool as they can get away with while still receiving the benefits of polyester. We prefer at least 75% merino wool in our blended fabrics. In our testing, it was no surprise the 100% merino shirts were the softest of the bunch.
Nylon: Another manmade fiber, nylon can add impressive durability to fabric blends. Garments like the Ridge Merino Journey Merino Wool Shirt incorporate a percentage of nylon into their weave and gain strength in return. It doesn’t take much to move the needle in terms of added durability, and we found a 20-30% nylon blend to be preferable.
Technologies like the Nuyarn used in the KUIU ULTRA Merino 120 LT SS Crew-T draft merino wool around a nylon core in order to offer the benefits of nylon while avoiding compressing the merino wool. Many other brands also offer similar nylon/merino blends, and all with the same effect.
TENCEL Lyocell: A branded fiber that comes from the pulp of eucalyptus trees, Lyocell is similar to rayon in construction but offers a highly sustainable process where both solvent and water are recycled during the weaving.
Garments that use Lyocell in their blends have high-strength properties due to the high tenacity of the fabric.
Another important aspect to consider when shopping for a merino wool layer is thickness and weight.
When it comes to weight, you’ll come across something written as GSM or g/m² — the weight of the material. Simply put, the lower the number, the thinner the material. For all-year-round layers, you’ll want something on the lower side, like around 120 to 180 g/m². And for extra warmth, you’ll want to go higher.
As for thickness, it’s all about the microns (µm) — the diameter of a single wool fiber. The lower the number, the thinner it is. It also means it’s softer and more expensive. In our opinion, the lower the micron, the more you’ll want to live in it, but you’ll need to take extra precautions due to its delicateness. For reference, the average human hair is about 70 microns thick, while the average merino wool fiber is between 15-20 microns.
Fine merino: Fine merino represents the division between true merino fibers and fibers that are sourced from merino sheep that have been crossbred with another breed for enhanced durability (but greater itchiness). These fine fibers are typically between 20 and 18 µm, and are the greatest portion of wool shorn from merino sheep. Durable shirts like the Ibex 24-Hour Short Sleeve Tee are made with merino in this tier.
Superfine merino: Superfine merino fibers take the softness up another notch, and are typically 16-18 µm. These fibers rival cashmere for its plushness, and will come with some additional cost for garments made with it. Some of our favorite merino shirts like the Unbound Merino Crew Neck and Ridge Merino Solstice Lightweight Pullover Hoodie are made with superfine merino.
Ultrafine merino: The most premium merino wool, these fibers are sub 16 µm and are rather delicate for true everyday wear for outdoors folk. But for the money ($$$), this is the best stuff you can get your mitts on.
We included a variety of shirts on this list: tees, long-sleeve tops, and even some hoodies. Each has advantages, depending on the type of activity you intend to engage in.
For those who need something for primarily cold temperatures, a layer that is tighter-fitting with loads of mobility that won’t feel restrictive under an extra one or two layers is recommended. Others who want something that can be worn all year, like our staffers, should go for something looser with a more relaxed fit.
However, we did not include all of the merino wool layers under the sun. We focused on shirts because they are versatile for a variety of weather conditions and activities. Some of the layers we tested are a little more sporty, while others, like the Unbound Merino Crew Neck, have a classic cut that’s a bit more versatile. If you are looking for winter-specific merino base layer sets, zip-up merino layers, or merino underwear (yes, it’s a thing!), we’ve got separate coverage on that, too.
Layers that come in an assortment of colors are always welcome — they mix things up from the monotonous black and gray we often see. However, while we love mixing things up, our testers have routinely noticed layers that come in pastel colors tend to be sheerer than navy, black, and dark gray.
Keep this in mind if you don’t want your undergarments showing through, unless you strictly use them as a base layer and will always be covered.
When you buy a merino wool shirt or garment, you aren’t just buying, you are investing. Investing in a higher-quality, naturally odor-wicking, and hopefully much longer-lasting layer. Synthetics are great, and there can be high-quality synthetic blends that have the same properties, but many folks swear by merino.
If you know you want a natural fabric that comes with all the soft, cooling, and wicking properties that merino has, keep the price in mind ($80 for a tee?!). It sounds ridiculous at first, but the price does truly reflect the quality of merino wool fabric.
Why the higher price in the first place? Merino wool is a more expensive fabric — more time-intensive to produce, expensive to import, and more fragile to work with compared to thicker synthetic yarns. So, we always weigh that factor when purchasing anything made with merino.
Merino wool is a natural material, meaning it doesn’t come from manmade plastics or synthetics. It’s lightweight and soft to the touch. It wicks away moisture and odors, and it helps regulate body temperature. All of that wrapped into a single fabric. No wonder humans have been using and wearing wool since 10,000 BCE.
However, because of merino’s great properties, it is in high demand and usually more expensive than other fabrics. The narrow sourcing and supply chain of merino wool also contributes to its market value. The majority of the wool on the market is produced in Australia, Argentina, and New Zealand.
In simple terms, yes. When it comes to exercising or spending lots of time in the outdoor elements, double yes. Merino is better in the sense that it is a natural and porous fiber. So, if you are sweating, that sweat can escape — this is what makes merino a natural at regulating moisture and body temp, wicking away odor, and cooling.
Cotton is an especially thick synthetic fabric, much different than lightweight or nano-spun synthetics, and much different than merino wool.
Heavy wool blankets or wool-lined slippers might evoke ideas of itchy, coarse fabric, but put those thoughts aside — merino wool is different. Merino wool is notoriously fine — with fine, fragile, and soft fibers.
Merino garments are even measured by the tiny diameters of the fibers, called microns. Most merino wool shirts we tested used merino wool that measured between 17.5 and 20 microns.
And the smaller the microns, the finer the fabric. If you are looking for the softest merino layer money can buy, you’ll want to look somewhere in the 15- to 17-micron fabric range.
Merino wool (wool from a sheep) naturally traps air and retains heat to keep you warm. But, thanks again to its porous fiber nature, it’s still breathable at the same time.
The fact that merino wool both retains heat and wicks away sweat — it works to both warm you up and cool you down — is one of its best properties. Wool keeps you cool by letting sweat escape through the fibers and away from your skin and body. This means you won’t get clammy or chills, and it also helps with wicking body odor.
Other fibers — synthetics or plant-based fabrics — are not as fine, porous, or breathable. They’ll do the job, but not as good a job. (That being said, our staff has a great time testing the latest in bio-based fabrics — unique layers sewn with everything from bamboo to hemp to corn.)
You’ll want to treat your merino shirts and layers with care. Because merino is a natural fiber, you also don’t want to use bleach, scents, or fabric softeners that can clog up the wool and prevent merino from doing all the things it does naturally.
Washing every few wears — sometimes even just once or twice a month — with cold or warm water and a mild soap is all you need. Even when we wear a lot of merino wool when outdoors, we try to wash sparingly. And we always air dry or hang it to dry.
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Mary Murphy is the Managing Editor of GearJunkie. She has been writing about hiking, running, climbing, camping, skiing, and more for seven years, and has been on staff at GearJunkie since 2019. Prior to that, Mary wrote for 5280 Magazine in Denver while working as an outdoor instructor teaching climbing, kayaking, paddleboarding, and mountain biking. Based in Denver, Colorado, Murphy is an avid hiker, runner, backpacker, skier, yogi, and pack-paddleboarder. Mary also serves as the leader of AllGear Digital’s DEI Committee.
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