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A merino crew-neck top blended with bamboo, the Le Base crew is soft and silky—it’s one of the most comfortable base layers we tried.

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Le Bent Base Layer and Trail Socks Review - Active Gear Review

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Softer Than a Bamboo Stalk - Le Bent Base Layer Review - The Backcountry Ski Touring Blog

Baselayer Roundup — 2020 | Blister

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You may be surprised to discover that you actually don't have to pay an arm and a leg for a superb Merino wool top. The Meriwool Merino 250 Long Sleeve offers near-top-quality performance at a fraction of the cost of most of the 100% Merino tops we tested. Even though it is firmly in the midweight category, the extra-fine spun wool used to create this layer is more breathable than other directly comparable models, making it a great option for folks engaged in high-output activities like ski touring. Couple that with a slim, stylish fit, and you have a layer you can take from the mountain straight to après-ski.
Though soft, the Merino wool is slightly itchy at first and takes some breaking in &#40;read: responsible washing and drying&#41; before it is snuggly-comfy. We hope that a future design of this shirt moves the seams off the shoulder top, which can rub when wearing a heavy pack. One thing you do lose with the price of the Merino 250 is durability: the extra-fine fibers are no match for anything abrasive, so keep this base layer away from your rock climbing and canyoneering trips. Beyond these small critiques, this layer presents a reasonable entry point into all-natural base layers. It is the perfect companion for cool-weather camping during the shoulder seasons, works well for both resort and backcountry skiing, and is certainly stylish enough to be worn casually.
Read more: Meriwool Merino 250 Long Sleeve review

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The Ridge Merino Aspect Midweight is a high-performing Merino wool base layer whose features far exceed the modest price tag. Constructed with 84% Merino wool and 16% nylon, it is one of the softest base layers that we've tested, while the nylon increases both durability and structure. Naturally odor-free, this layer can be worn for weeks between washes, and the thoughtfully placed flatlock seams increase comfort and prevent chafing when shouldering a heavy backpack. 
While we do not consider this a midweight as advertised, it is an exceptional lightweight garment that is easy to layer over the top of. The slim-fitting, versatile design effectively traps body heat when temperatures drop and dumps excess heat when you pick up the pace. While not the warmest layer that we've tested, this is a great choice for the base of your cold-weather layering system.  
Read more: Ridge Merino Aspect Midweight review

The Patagonia Capilene Thermal Weight Zip-Neck quickly stood apart from the competition in terms of warmth and breathability. Our lead tester loves this layer as a stand-alone piece for efficiently shedding sweat accumulated on fall trail runs as well as the base of her cold weather kit while rock climbing during those crisp October nights. While not a thermal weight as advertised, the polyester blended fabric and micro-grid fleece interior gave a memorable performance in terms of exceptional breathability and moisture-wicking capabilities. 
Patagonia advertises a Polygiene odor control treatment for the Capilene Thermal, but we found this layer to retain body odor almost immediately, especially when used several days in a row. And while we appreciate the thumb loops in terms of layering ability, the low-quality construction &#40;basically just an elastic band&#41; doesn't inspire confidence they will last for the life of the base layer. That said, this layer offers excellent thermoregulation and breathability thanks to the air-permeable Polartec fabric and the long zip neck. These work together to effectively dump heat and excess sweat during those high-intensity mountain pursuits. 
Read more: Patagonia Capilene Thermal Weight Zip-Neck review

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A top that is likely to earn its place as your go-to for all cold-weather activity, the SmartWool Merino 250 Crew continues to shine in this category. This remarkably versatile mid-layer offers superior comfort next-to-skin, and its 100% merino wool weave provides excellent temperature regulation, moisture-wicking capability, and all-natural antimicrobial qualities. We've worn it for days on end, both at home and out on multi-day backcountry trips. Unlike its synthetic competitors, it somehow manages to be very acceptable &mdash; stench-wise &mdash; after many days between washes. This layer performs well in a wide range of temperatures, allowing you to quickly transition from static cold to high-exertion, all while staying warm, dry, and comfortable.
As expected with natural fibers, this top will begin to slouch and sag a bit through consistent wear. The Merino 250 Crew &#40;and all other merino tops we tested&#41; requires special care when laundering to ensure the garment's longevity. When the fabric becomes completely saturated, this top is comparatively slow to dry. From the crag to the mountain and then back down for a night on the town, the SmartWool Merino 250 is comfortable and stylish enough to wear every day. It excels in practically any cool- or cold-weather activity, from resort skiing to winter alpine ascents to hanging on chilly mornings on desert climbing or rafting trips.

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SmartWool NTS Mid 250 Pattern Crew | Blister

This merino wool shirt is fitted but not tight, and it wears well under backpack straps.

Especially loved by our snowsports testers because it kept them from overheating, this top is pieced together with different fabric panels, so it’s formfitting yet it doesn’t restrict movement, a rare combination for a wool garment.

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You may be surprised to discover that you actually don't have to pay an arm and a leg for a superb Merino wool top. The Meriwool Midweight Thermal offers near top-quality performance at a fraction of the cost of most of the 100% Merino tops we tested. Even though it is firmly in the midweight category, the extra-fine spun wool used to create this layer is more breathable than other directly comparable models, making it a great option for folks engaged in high-output activities like ski touring. Couple that with a slim, stylish fit, and you have a layer you can take from the mountain straight to après-ski.
With the benefits of increased breathability, you will sacrifice of a bit of warmth &mdash; don't expect this layer to be quite as warm as other 250 g/m² options included in this review. Though soft, the Merino wool is slightly itchy at first and takes some breaking in &#40;read: responsible washing and drying&#41; before it is snuggly-comfy. We hope that a future design of this shirt moves the seams off the shoulder top, which can rub when wearing a heavy pack. Beyond these small critiques, the Meriwool Midweight Thermal presents a reasonable entry-point into all-natural base layers. It is the perfect companion for cool-weather camping during the shoulder seasons, works well for both resort and backcountry skiing, and is certainly a stylish top to be worn casually.

Analysis: Will Merino Wool Keep Us Warm While Snowshoeing?

If you’re a first-time hiker, backpacker, or camper, this is a decent top to get you out there.

The REI Co-op Midweight Base Layer Crew is a great choice for those seeking a highly functional synthetic base layer with an affordable price tag. This garment offers enough warmth for those in-between-season days and is available for a fraction of the cost of its top-performing synthetic competitors. It also has durable features such as flatlock seams and thumb loops that give us confidence this layer will be around for many seasons to come. 
We were disappointed by the synthetic polyester blended fabric, as we noticed it retained odor almost immediately. And while the fabric successfully wicked moisture and sweat away from our skin, this layer couldn't efficiently release moisture through the tightly woven fabric, so it took longer to dry. This sometimes would mean sacrificing precious warmth during colder temps, so we do not recommend this layer for high output activities nor for the depths of winter. Overall, our testers were happy with the slim-fitting, durable design that kept us warm during the shoulder seasons or as the base of our layering system for moderately cold weather adventures. 
Read more: REI Co-op Midweight Base Layer Crew review

The Winter Guide to Baselayers

The Best Budget Base Layers: REI Co-op Midweight Base Layer Review

Infinitely stretchy and stylish, the Cotopaxi Liso Top earns top marks from us in almost everything except absolute warmth. The handsome cut and smooth fabric of the Liso performs excellently as a base layer, allowing you to move freely underneath the shirt and layer up with whatever kit you'll need throughout the day to stay warm, dry, and comfortable. We especially love the addition of thumb loops that keep the extra long raglan sleeves from riding up while we're riding down slopes at Mach 4. Once you're back in the lodge, strip down to just the Liso Top while sipping on hot chocolate and still be confident that this base layer makes you look good all on its own.
If you're ultimately looking for the warmest base layer out there, the Cotopaxi Liso won't fulfill all your needs, as it is thinner and not as warm as others out there. It's also less warm at the same weight than its wool counterparts. The synthetic fabric will develop a funk if you haven't washed it after a few days of use, despite the Polygiene application applied to the fabric. Be mindful when washing the Liso: all that stretch is accomplished by using a hefty amount of spandex in the fabric, and this will lose its stretchiness after enduring too many dryer cycles. 
Read more: Cotopaxi Liso Top review

Emerging Gear: Say Goodbye to 2020 With These Hot New Outdoor Goodies

This crew-neck shirt is a good option for sports practice, obstacle races, or any activity where you might get really dirty, because it’ll stand up to a lot of washing.

Base Layer Comparison