The Smartwool Merino ¼ Zip baselayer is our go-to for outdoor play. The fabric is super cozy and warm, providing a wide range of thermoregulation through all four seasons. This Editors' Choice winner is our top recommendation for its versatility and bomber performance while skiing the bumps and hiking up majestic mountains.
A look at the fit of our Editors' Choice award winner.
This is one of warmest base layers tested. Constructed of 100% Merino wool, this midweight layer features a wide range of thermoregulation. We tested in temperatures ranging from the mid-70s to the double negatives. In all situations, we found applicable uses! In Northern Ontario, the soft wool insulated and generated heat under a mid-layer and jacket, keeping us toasty while skating and lake hiking. In Colorado, we ran and hiked, noting the cozy wool did a great job wicking away sweat. When caught in a rainstorm, this layer insulated and still kept us warm. As a result, it thrives in all conditions, making it perfect as a wear alone piece in warm months and a base layer in the colder part of the year.
The Smartwool Merino 250 Crew features 100% wool and offers terrific warmth; however, it isn't as warm as the ¼ Zip, simply because it doesn't cover the neck. This lead to more heat loss during cold months. The ¼ zip also allows more venting then the Smartwool 250 Crew which provides a broader range of thermoregulation.
If you prefer Smartwool products, they have a plethora of different weight options using similar fabric. Simply check out the different weights if you prefer more or less warmth overall.
In addition to being warm, this layer is ultra-breathable. When considering all the different layers on an afternoon run in the winter, our go-to is typically this layer amongst some other synthetic competitors. Its tighter fit facilitates better wicking ability and sweat does not hang around in the fabric. Also, the zip neck provides better venting then the Smartwool Crew and other Merino wool contenders.
When skiing in Alaska and running in the desert, we were able to test the limits of breathability. In a layered system, the 100% merino wool fibers do a great job wicking away moisture from the skin. This kept us dry. The same was true for our desert running adventures. In both cases, layered and as a stand-alone top, it performs well, breathing when needed. As a key function of any base layer top, it reigns supreme in this metric. Take it with you for any endeavor you decide to pursue.
Trail running during an after-work run. The Smartwool 1/4 Zip sufficed on this trip providing great thermoregulation.
Comfort & Fit
Oh boy…can we gloat about the coziness of this fabric for a second? The Smartwool ¼ Zip is a go-to for everyday adventures. We like to wear it everywhere, though its best place is in the backcountry. The Merino Wool that Smartwool uses is super comfortable and soft. It doesn't itch, even when wearing it against the skin for days on end. It doesn't get smelly and seems to dry super quickly. Also, it stretches just enough for a fit that every one of our testers loves.
We tested fit with a variety of testers from short to tall. This particular piece features a medium fit, with the hem coming down just past the hips. The arms are long enough for all body types, and size is true to fit. Since the fabric stretches, it doesn't confine through the shoulders or the bust.
One of the most comfortable base layers in this review!
Given the relaxed fit, we found that it could easily be worn all day long, for multiple days on end. Put it on underneath a jacket or overtop a tight tank top or t-shirt. Testers of all shapes and sizes agree that fit is versatile yet precise. Overall, the Merino ¼ Zip has excellent comfort features and "next-to-the-skin" comfort that will have you adventuring for days, weeks, and months. During our testing period, we brought this with us on an adventure as the sole piece of gear. It sufficed during a month-long backpacking adventure in Northern Europe.
This top comes down just around the hips and features a little stretch for all body types. While it doesn't have the longest arms or torso, it still fit our longer armed testers comfortably.
Layering can be a pain in the butt with this top, similar to other Merino wool contenders. With a face fabric that features a soft and "grabbier" fabric, we often found it hard to get an insulating layer over top that featured a fleece lining. That said, upper layers with a slippier face fabric did just fine.
The top features a thinner fabric design and long arms that make it easy to pull a midweight insulating layer over top. The arms are longer than other Merino wool options so they can be used to pull through without bunching. In addition, because it's not super fitted, a layer can fit underneath. Aside from that, we didn't observe it riding up for bunching in weird places while on the move. It also fits underneath a jacket nicely.
Here we wrestle on the Patagonia R1 that has a fleece-lined interior. The grabbier face fabric of the Smartwool 1/4 Zip baselayer makes it a little harder to layer than those with a slipperier face fabric.
We were pretty impressed by the rate of drying in this merino wool contender. In our tests where we dunked it underwater until completely saturated, we weren't surprised to learn that it would absorb a lot of water. We thought, for sure, that it would be one of the longest to dry; but, we were surprised when it took only 90 minutes to dry, similar to other Merino wool contenders.
In addition, when getting caught in a rainstorm, the material didn't provide much water resistance. However, when a subtle ray of sun shone after the storm, the shirt proved to dry pretty quickly. As a result, we might recommend it for use as a base layer for cold, humid, and wet weather. However, as a stand-alone piece, we would recommend a synthetic that doesn't absorb as much water and dries out more quickly for wet weather.
Utilizing a 100% Merino wool construction, this contender is not very durable. While we did not observe any serious wear and tear during our testing period, we noted some stitching flyaways and pilling of the fabric after just a few washes.
We wouldn't choose it as a wear alone top for high-friction sports like crack climbing or canyoneering as the fabric would instantly tear with intense abrasion. Instead, we would choose it for day hikes or wear underneath other layers.
While this top didn't earn any holes, we noticed some pilling around the wrists and some stitching fly-aways. Although this a great all-around use top, it sure isn't incredibly durable.
With the largest range of thermoregulation, this versatile base-layer top is recommended for outdoor play throughout the four seasons. Wear it out with friends or while hiking in the backcountry; just avoid wearing using it as a stand-alone piece if you plan on shimmying through tight sandstone slots or bushwhacking through the backcountry. The fabric won't hold up to the friction and snags. Its cute design works for wear around town as well as trudging through the backcountry.
Here we take a training winter run after work with the Smartwool 1/4 Zip in a layered system. After the run where we transitioned from hot to cold, we felt comfortable. This Merino wool competitor thermoregulates well!
For just $100, you can take home one of the best performing base layers on the market. While it's not the most durable, it certainly holds its value with its wonderful comfort and thermoregulation.
This Editors' Choice winner is perfect for all-year-round play. Its wide range of thermoregulation in addition to its cozy fabrics will have you wearing it day to day. Take it with you on your next great adventure.