Hands-on Gear Review

Smartwool Merino 250 Base Layer Crew - Women's Review

This 100% Merino wool Top Pick for everyday wear is cute, warm, and functional.
By: Amber King ⋅ Senior Review Editor  ⋅  Mar 27, 2018
Price:  $105 List  |  $78.93 at REI - 25% Off
Pros:  Natural 100% Merino wool fibers, warm, soft, cute patterns, wide range of thermoregulation, odor resistant
Cons:  Sticky layering, poor durability
Manufacturer:   Smartwool

#4 of 9
  • Warmth - 20% 7
  • Breathability - 20% 9
  • Comfort and Fit - 20% 10
  • Layering ability - 15% 6
  • Drying Speed - 15% 6
  • Durability - 10% 5
  • 1
  • 2
  • 3
  • 4
  • 5
Top Pick Award

Our Verdict

Do you seek a base layer that can be worn every day? The Smartwool Merino 250 Crew is one of the most comfortable contenders tested. This top is offered in a plethora of cute patterns that will not only have you looking adorable in the mountains but around town as well! The 250-g of Merino wool is soft to the touch and feels great against the skin. Wear it as a stand-alone piece in the Fall and Spring, or as apart of a layering system in the winter time. It thermoregulates throughout one of the widest ranges tested, with similar performance to our Editors' Choice winner, the Smartwool Merino 250 ¼ Zip.

While our testers love this piece and give it a Top Pick for Everyday Wear, it is the least durable option tested. Our testing team observed stitching fly-aways, pilling, and even hole after extended use (in just three months). For $105, we weren't impressed by the value. That said, if you don't plan on wearing it for extended periods of time with a backpack or while shimmying through slot canyons, this may still be an excellent option for you!

Compare to Similar Products

Our Analysis and Test Results

Name Change: Smartwool just changed the name of this base layer from the Smartwool NTS 250 Midweight Base Layer Crew to the Smartwool Merino 250 Base Layer Crew.

Enjoy this Top Pick for everyday use — every day! This is our favorite piece to wear when hanging out with friends or while taking on the town. It provides the best thermoregulation of any piece tested. The Merino wool is super cozy, itch-free, and comfortable but it's not very durable. Enjoy it throughout the year as a stand-alone piece of as apart of a layering system.

Performance Comparison

The Smartwool 250 Crew is comfortable for wear-all-day (and all-night).
The Smartwool 250 Crew is comfortable for wear-all-day (and all-night).


As a stand-alone midweight baselayer, this 100% Merino wool top is one of the warmest layers tested. Featuring 250-grams of Merino wool, the wool fibers generate and lock in warmth on days that dip into the double negative digits. While it's not the warmest baselayer in this review, it certainly provides great warmth in a layering system. Since the face fabric isn't super wind resistant, it's not the warmest when worn on its own in a windstorm. It earns an above-average score of seven out of ten for warmth.

Featuring a crew-collar cute, this base layer doesn't provide as much protection, nor does it lock in warmth like our Editors' Choice winner, the Smartwool Merino 250 ¼ Zip. The face fabric isn't super wind-resistant as a wear-alone piece like the synthetic Arc'teryx Rho LT Zip Neck, our Top Pick for Versatility. In comparison, the Smartwool is warmer when integrated into a layering system, but when worn alone it felt much colder especially since it doesn't offer any wind resistance. If you search for the warmest layer for your polar expedition, check out the Icebreaker Tech, loaded with 260-grams of 100% Merino Wool.

Smartwool offers both light and heavy-weight options. Be sure to check out different weights of wool if you are in need of a lighter or heavier layer.


Constructed of 100% Merino wool, the Merino 250 Crew provides amazing breathability and a wide range of thermoregulation. We took this layer on hiking, running, and skiing adventures in the high country of the San Juan mountains. While out on the trails, we encountered shady and snowy nooks laced with warm sunny trails. While traipsing from warm to cold temperatures, we felt warm when it was cold and cool when it was warm. We didn't take any layers off, nor did we have to put any on. As a true thermoregulator, this top scores an eight out of ten for breathability. The fabric also doesn't hold moisture, keeping you warm in cold temperatures when standing still.

If the best for breathability is what you seek, the the synthetic Patagonia Midweight Capilene Crew scores a perfect ten. While it doesn't have the broadest range of thermoregulation like the Merino 250 Crew it certainly wicks away moisture quickly, making it an excellent option for cold weather running or cross-country skiing. The only downside is that it's not very warm.

Other impressive merino wool options that are as breathable include the Icebreaker 260 and WoolX Hannah. The Icebreaker is fantastic at thermoregulation, but the fabric is a touch thicker, making it a little less breathable than the Smartwool. The WoolX Hannah is of a lighter weight but the wool is similar in thickness to the Icebreaker, earning a lower score than the Smartwool. Overall, the Smartwool Midweight Base Layer (both zip neck and crew) are the best when it comes to breathability and thermoregulation.

Comfort & Fit

Boasting comfort and coziness, our testers couldn't get enough of the soft 100% Merino wool construct. As a result, it earns our Top Pick for Everyday Wear. From the moment we put it on, we didn't want to take it off. The Merino fibers are thin and soft, feeling luxurious against the skin. The fabric has just the right amount of stretch, which allows one to pull the cuffs over the hands when the wind blows. The fit also provided great coverage for all our testers. Like the Smartwool Merino 250 ¼ Zip, this base layer earns a perfect ten for comfort & fit.

While all the Merino base layers felt so good on the skin, the only exception is the Kari Traa Rose Half Zip that felt a little scratchy on the skin. If it's a comfortable and cozy synthetic base layer you seek, take a look at the skin-tight Arc'teryx Rho LT featuring a fuzzy-lined interior and wind-resistant face fabric. The Smartwool does not have these fleecy features that some folks may prefer.

A look at the fit of this super comfortable base layer.
A look at the fit of this super comfortable base layer.

Layering Ability

Even though we were able to comfortably wear layers over and under the Merino 250 Crew, we found that it would grab other layers and slowly ride up under a fleece-lined mid-layer, exposing our skin. If this had happened once or twice, it wouldn't be so much of problem. However, it happened all the time and was a deal breaker for some of our testers. As a result, it scores an average six out of ten for layering ability.

Options with a less-grabby face fabric are typically synthetic competitors with a tighter fit. For example, the REI Co-op Midweight Base Layer Crew has a polyester-blend construct that slides easily with less friction. The Arc'teryx Rho LT is another fantastic option, scoring a perfect ten in this category due to its Torrent fabric and tight-to-the skin fit.

Layering this Smartwool 250 under a mid layer while skinning up Red Mountain Pass in Colorado.
Layering this Smartwool 250 under a mid layer while skinning up Red Mountain Pass in Colorado.

Of the merino wool competitors, the Kari Traa Rose Half Zip is the most layerable. Even though its face fabric is constructed of wool, the knit is finer, making it a little less friction than Smartwool and other merino wool contenders.

Drying Speed

Of the Merino wool layers, this shirt took the longest to dry - at about 100 minutes in our dryer tests. Other Merino options including the Smartwool 1/4 zip and WoolX Hannah took about 90 minutes. That said, this layer doesn't absorb as much water as the Smartwool 1/4 Zip or the Icebreaker 260 Midweight. It scores a six out of ten for drying speed.

If you seek a layer that dries quickly, synthetic is the way to go. Consider the uber breathable Patagonia Capilene Crew that took only 40 minutes to dry. Or the REI Co-op Midweight Crew that took only 50 minutes to dry. These options are ideal for wet weather or situations where you might need your layer to dry quickly for the next round of use.


We were not impressed with the durability of this Smartwool top, and it earned one of the lowest scores in our review (five out of ten). After a close inspection of the seams and fabric after use, we found a pilling and stitching fly-aways throughout the shirt. In past reviews, and this one, a hole rubbed into the face fabric after three months of use. Unlike any other layer tested, this proves to be the least durable, making it a deal-breaker for some of our reviewers.

While Merino wool base layers aren't typically as durable as synthetic competitors like the Arc'teryx Rho LT or REI Co-op Midweight Crew, the Smartwool Crew showed exceptionally more wear and tear than others. For example; while the WoolX Hannah showed some pilling, there were no stitching fly-aways. The Icebreaker Tech 260 Midweight features a heavier construct and proved to be the most durable Merino wool base layer tested. The Smartwool ¼ Zip also showed less wear and tear, but show pilling after use (earning a bit of a higher score). That said, there are more durable pieces out there.

The 250 Crew rubbed a hole through the fabric and experienced stitching flyaways throughout the garment. While this is a super comfortable and cozy shirt  it's not very durable.
The 250 Crew rubbed a hole through the fabric and experienced stitching flyaways throughout the garment. While this is a super comfortable and cozy shirt, it's not very durable.

Best Applications

As one of the cutest base layers tested, it's our Top Pick for everyday wear. Whether you're strolling around town or hiking to the top of a mountain, this layer will keep you cozy and warm throughout the day. As a midweight option, it's perfect as a wear-alone piece in the Fall or Spring or as apart of a layering system for cool to cold days. If you seek long underwear that will keep you warm in temperatures similar to that found in the Antarctic, opt for a heavier-weight construct (not a midweight).


We realize that merino wool tops are more expensive and less durable than most synthetics. However, we weren't thrilled that this $105 (retail) 100% Merino wool layer showed serious wear and tear after just three months of use. We love the comfort it provides, but there are less expensive merino options like the WoolX Hannah for just $79 that offer a better value. Or if you're just interested a high-value option, be sure to look at our Best Buy award winner, theREI Co-op Crew for just $50.


The Smartwool Merino 250 Crew won our Top Pick for everyday use for its wonderful combination of style, thermoregulation, and comfort. Wear it around town or while you tackle your next big adventure. Just be sure to avoid it for high-friction activities that might tear or wear out the fabric.

Amber King

You Might Also Like

OutdoorGearLab Member Reviews

Most recent review: March 27, 2018
Summary of All Ratings

OutdoorGearLab Editors' Rating:  
  • 1
  • 2
  • 3
  • 4
  • 5
Average Customer Rating:  
Rating Distribution
1 Total Ratings
5 star: 100%  (1)
4 star: 0%  (0)
3 star: 0%  (0)
2 star: 0%  (0)
1 star: 0%  (0)

Have you used this product?
Don't hold back. Share your viewpoint by posting a review with your thoughts...