Base Layer Tops
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How we choose: The best base layer tops highlighted here were selected based on 151 reviews of 110 products. Our top picks are those that are readily-available in the United States and have received the highest overall ratings from reviewers.
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Fjallraven Bergtagen Woolmesh Sweater
The Fjallraven Bergtagen Woolmesh Sweater is a base layer top that utilizes wool in three different weaves to maximize heat retention in key areas (chest, back) and breathability in others (stomach, underarms). It’s a total home run of execution and since I received this top for testing I have worn nothing else. It’s exceptionally well tailored, durable, doesn’t stink on multi-day trips, and you’ll have no fear around a fire. The only possible negatives are more inherent to wool, than this product—it takes longer to dry.
Reasons to Buy
- Comfortable
- Durable
- Breathable
- Sleeve and torso length
- No stink factor
- Tight neckline (keeps snow out)
- Fire resistant (no worry about sparks)
Reasons to Avoid
- Wool takes longer to dry
- No trail to town use
- I usually prefer a base layer with a hood
- I'd love to see thumb loops added
PREAMBLE Fjallraven is right up there with Arc'teryx in the confusing naming scheme of their products. The Woolmesh Sweater is part of their Bergtagen line (Bergtagen is a Swedish word used to describe the feeling of being captivated and humbled by the mountains, awesome name), which includes the base layer (two top options and two bottom options, both men's and women's), mid-layer insulation (two different jackets for both men and women as well as an elephant style sleeping bag), outer shell (pants and jacket, both men's and women's), and a work layer (pants and jacket, both men's and women's).
Read more: Fjallraven Bergtagen Woolmesh Sweater review (1)
Voormi River Run Hoodie
A super-comfortable and versatile Merino blend hooded shirt, excels as a sun or wind shirt. This is the first time I’ve really tried a long-sleeved sun protective shirt, and I was pleasantly surprised how comfortable it is in warm conditions. Though it is marketed as a sun shirt, it is much more than that.
Reasons to Buy
- Soft comfortable hand
- Lightweight
- Breathable
- Great fit
- Versatile
- Machine washable
Reasons to Avoid
- The hem could be a little lower for better coverage of my long waist
- Thumb loops can rub against your hand with hiking poles or handlebars
Morning walk in the foothills Having read several super positive reviews about this hoodie, I wanted to give it a try, but was put-off a little bit by the price tag. But having recently moved to the Sierra foothills, where it is generally colder than the central valley, I went for it anyway, and was not disappointed. Fit and Comfort: I would consider the fit to be on the "athletic" side. I wasn’t quite sure whether to order the XL or the XXL. While I usually fit XL in most shirts, occasionally they can be a little tight (Icebreaker shirts are a good example of this.
Read more: Voormi River Run Hoodie reviews (2)
Black Diamond Solution 150 Merino Base Crew
Black Diamond's Solution 150 Merino Base Crew is a lightweight, polyester-reinforced merino wool base layer. Cool enough to wear under light shell clothing for high intensity activity at around-freezing temperatures without overheating, but easily layered over for use in colder conditions or at lower intensity. Stretch fabric gives a comfortable fit even on a slim frame and dries a little faster than 100 percent merino.
Reasons to Buy
- Comfy fit and feel
- Light base layer for intensive activity
- Also good for cold-wet days in summer
- Lightweight in the pack
Reasons to Avoid
- Polyester core may shed microplastic fibers in wash water
- No long sizes
(Preliminary review based on the first month of use) Black Diamond’s Solution 150 Base shirts and long underwear are lightweight, polyester-reinforced merino wool base layers. They are light enough to wear under light shell clothing for high intensity activity at around-freezing temperatures without overheating, but easily layered over for use in colder conditions or at lower intensity. BD has supplied me with both a crew neck top and ¾ length bottoms for testing. Much of what I have to say about the one will apply to the other and so may be duplicated in both reviews.
Read more: Black Diamond Solution 150 Merino Base Crew review (1)
Kari Traa Rose Long Sleeve
The Kari Traa Rose Longsleeve is a 100 percent merino base layer that is comfortable, warm, and durable. It's thin enough to layer without restricting movement, and incorporates a range of colors and sizes to appeal to a variety of adventurous ladies! Just be prepared to size up as this base layer runs SMALL!
Reasons to Buy
- Soft (for merino wool)
- Warm
- Breathable
- Fit is snug without restricting movement
- Thin enough to layer easily
- Stays in place
- Variety of color and size options (up to 4XL)
Reasons to Avoid
- Runs small—plan to order one size up
Testing Conditions: I tested the Kari Traa Rose Longsleeve from December 2018 to December 2019 as a member of the Trailspace Review Corps. Testing conditions ranged from -25 to 20 degrees Fahrenheit in the following activities: hiking, fat biking, snowshoeing, backcountry skiing, alpine (resort) skiing, and nordic skiing. Rose Longsleeve front view Fit & Comfort: For those who aren't familiar with Kari Traa, the Norwegian brand was developed by its namesake, a female Olympian freestyle skier. The Rose Longsleeve is a base layer made of 100 percent merino wool.
Read more: Kari Traa Rose Long Sleeve review (1)
Patagonia Capilene Air Hoody
The Patagonia Capilene Air Hoody is Patagonia’s newest base layer design which utilizes a unique seamless knit construction that is composed of 51 percent merino wool and 49 percent Capilene recycled polyester that results in a very stretchy insulation layer that is both light and warm. The integral hood is close fitting and works well under other hooded jackets, hats, or a climbing helmet, but I found it most useful as a scrunchie for keeping my neck warm. Overall this is a great base layer, especially for colder conditions.
Reasons to Buy
- Very warm
- Not itchy for wool
- Seamless design adds to comfort—very flat transitions
- Hoody makes a nice scrunchie around neck
- Doesn’t hold odors
- Very breathable
- Responsibly sourced wool and recycled polyester
Reasons to Avoid
- Might be too warm for many activities
- Some shrinkage in the body and sleeve length
- Pills pretty easily
Overview The Patagonia Capilene Air Hoody is Patagonia’s newest base layer design which follows Patagonia’s long tradition of developing new fabrics with improved performance while also trying to find ways to minimize the impact on the environment. The Capilene Air Hoody fabric is a unique a 3-D seamless knit construction that utilize fibers made from 51% responsibly sourced merino wool and 49% Capilene recycled polyester. The resulting hoody is light, warm and very comfortable to wear.
Read more: Patagonia Capilene Air Hoody review (1)
Helly Hansen HH LIFA Stripe Crew
An all-time classic design. Form meets function.
Reasons to Buy
- Super-light
- Washes in seconds
- Dries as quickly as it washes
- Much more durable than it appears
- Versatile enough for four-season use
- Outstanding wicking properties
Reasons to Avoid
- Unfashionable
- Not the most comfy
Every competing manufacturer has tried to persuade the public that the original HH vest is outmoded. It has no zips, pockets, or gimmicks, it isn't made of a new wonder material or rediscovered 'smart' wool. The look is like something from an '80s magazine. So why do they still get made—and sold all over the world—in large quantities? Warmth and wicking. The Lifa polypropylene meets both criteria, when your body is working near maximum and the weather is uncooperative. I even have an old white, long sleeved vest, which is perfect under a hot Spanish or Californian sun.
Read more: Helly Hansen HH LIFA Stripe Crew reviews (2)
Patagonia Capilene Air Crew
A relatively loose, very stretchy, and ridiculously breathable base layer. Due to the loose weave, wind runs almost literally right through it. This is a combination wool/synthetic layer that provides great warmth (under a shell or in still air) and wicks moisture well. Durability...well, be careful with it. Good for a wide range of temperatures and conditions.
Reasons to Buy
- Super comfortable
- Versatile
- Exceptional wool/synthetic combo
Reasons to Avoid
- Loose for a base layer
- Long sleeves
- Durability might be an issue
- Price
THE BASICS A couple of years ago, Patagonia started selling a line of base layers it called "merino air." The fabric was a very stretchy combination of 51% merino wool and 49% synthetic Capilene, which is Patagonia's outstanding synthetic wicking base layer material. I picked up a pair of the Merino Air Bottoms and have enjoyed wearing them. Then, for no particular reason, Patagonia stopped selling it. Last year, the knitted fabric returned, reincarnated as Capilene Air. Same knitted (Patagonia says "exploded") merino/capilene blend, same qualities as the last go-around. As you will read as I run through how this performs, it is a unique kind of base layer, easily the most interesting and useful wool blend layer I have used.
Read more: Patagonia Capilene Air Crew reviews (2)
Smartwool Intraknit Merino 250 Thermal 1/4 Zip
The Smartwool Intraknit Merino 250 Thermal Quarter Zip brings 100% Merino wool in a comfortable and warm weave. This shirt works as a base, mid, outer and only layer depending on conditions, activity and the wearer's temperament. Versatile enough to handle a wide variety of cold weather activities.
Reasons to Buy
- 100% Merino
- Comfortable weave against skin
- Quarter zip
- Breathes and wicks very well
- Slim Fit reduces excess fabric
- Layers well
- Long waisted for tucking
Reasons to Avoid
- Would have loved a half zip
Smartwool takes a technical leap forward with their newly designed Intraknit Merino 250 Thermal 1/4 Zip and I've had the pleasure of extensively testing it over the last four months. Along with their Intraknit Merino 250 Thermal Bottom, I've pretty much lived in this shirt over the Winter. Definitely enough testing to give you a comprehensive look at this versatile cold weather shirt along with my thoughts on the subject too. Before we dig into the review I thought it might be useful to go over a few basics about wool.
Read more: Smartwool Intraknit Merino 250 Thermal 1/4 Zip review (1)
Smartwool Lightweight Zip T
I urge all review-readers: as always, shop around. I saw this top for as much as $80, but with a few Google searches found it for $30 on clearance.Unlike the previous reviewer, I found the sizing chart to provide a good fit (I'm a small). I've been favorably impressed with this shirt. I did expect it to provide a bit more warmth, however. To give a better idea, I'm a hot person in general and frequently hike with this as my shirt in 60ish degree weather with a 28lb pack with no problems. I would roast alive if I tried that with a long-sleeved shirt with any kind of insulation.
Read more: Smartwool Lightweight Zip T reviews (4)
Outdoor Research Alpine Onset Crew
The Outdoor Research Alpine Onset Crew is a comfortable baselayer that blends merino wool with nylon and spandex to form a highly flexible, non-restrictive baselayer. It's best used for active pursuits in moderately cold temps, like hiking in chilly weather.
Reasons to Buy
- Soft
- Ample arm length
- Agile and non-restrictive
- Controls odors
- Very comfortable to sleep in
- OR's Infinite Guarantee for lifetime of the product
Reasons to Avoid
- Neck stretches after use
- Seams are beginning to show signs of wear
Conditions and Temperatures:I tested the Alpine Onset Crew baselayer top along with its bottom counterpart, the OR Alpine Onset Bottoms. These items are a part of Outdoor Research's Alpine Onset collection, which includes an array of men's and women's layers. As soon as the OR Alpine Onset Crew top arrived on my doorstep in the dead of winter, I put the baselayer on and have worn it pretty consistently since. I wore it every week for about three months, multiple days per week at times, and then sporadically as the temperatures rose for an additional two months. I’ve worn this crew top baselayer for three months through the fields and forests of central Pennsylvania while hiking, camping, hunting, mountain biking, and for general everyday...
Read more: Outdoor Research Alpine Onset Crew review (1)
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