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Smartwool Merino 250 1/4 Zip - Women's Review

Our favorite base layer with the best thermoregulation that we continue to love.
Editors' Choice Award
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Price:  $105 List | $105.00 at REI
Compare prices at 2 resellers
Pros:  Wide range of thermoregulation, cute, super cozy, great fit, fantastic breathability, no odor
Cons:  Lacks durability, absorbs water
Manufacturer:   Smartwool
By Amber King ⋅ Senior Review Editor  ⋅  Nov 8, 2019
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84
OVERALL
SCORE


RANKED
#1 of 10
  • Warmth - 25% 9
  • Breathability - 25% 8
  • Comfort and Fit - 20% 10
  • Layering Ability - 20% 7
  • Durability - 10% 7

Our Verdict

The Smartwool Merino ¼ Zip is our favorite baselayer. Winning our Editors' Choice Award for three years in a row, it will keep you warm while you tackle high peaks or descend snowy slopes. The 100% Merino wool construct is comfortable and warm, providing a wide range of thermoregulation in temperatures ranging from the double negatives to the sunny 70s. We wear it while hiking, biking, running, and skiing. In all situations, it performs super well. It drys quickly and keeps us warm when going up, eating lunch, then going down. It works hard to keep you dry, even on the sweatiest of endeavors.

Our testers generally prefer the added versatility of the 1/4 zip version of this shirt. However, we've also tested and loved the crew cut version of this shirt, and thoroughly believe that you can't really go wrong with either version.


Compare to Similar Products

 
Awards Editors' Choice Award  Top Pick Award   
Price $105.00 at REI
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Pros Wide range of thermoregulation, cute, super cozy, great fit, fantastic breathability, no odorGreat thermoregulation, exceptional at wicking, impressive durability, least itch factor of all wool tops testedCozy fleece interior, easy to layer, warm, high quality performance, versatile, stash pocket, tight fitGreat thermoregulation, comfortable and fitted fabrics, great patterns and colorsImmensely comfortable, quick to dry, lightweight, huge range of thermoregulation, no smell
Cons Lacks durability, absorbs waterNot very cozyMore expensive, not super breathablePoor durabilityLacks durability, expensive, harder to layer
Bottom Line Our favorite base layer with the best thermoregulation that we continue to love.Icebreaker uses the most comfortable wool in this seemingly lightweight base layer.This high performance synthetic is a Top Pick for pretty much any adventure you dream up.A great thermoregulator with some durability issues.An amazing balance of breathability and warmth with some layering issues.
Rating Categories Merino 250 1/4 Zip Merino 200 Oasis Crewe Rho LT Zip 185 Rock'N'Wool Long Sleeve Capilene Air Crew
Warmth (25%)
10
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9
10
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8
10
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7
10
0
8
10
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8
Breathability (25%)
10
0
8
10
0
8
10
0
7
10
0
8
10
0
10
Comfort And Fit (20%)
10
0
10
10
0
8
10
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8
10
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9
10
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9
Layering Ability (20%)
10
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7
10
0
9
10
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10
10
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9
10
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5
Durability (10%)
10
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7
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8
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9
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5
Specs Merino 250 1/4 Zip Merino 200 Oasis... Rho LT Zip 185 Rock'N'Wool... Capilene Air Crew
Fabric Weight Midweight (250-grams) Midweight (200-grams) Lightweight (185-grams) Midweight (185-grams) Midweight (147-grams)
Material 100% Merino wool 100% Merino Torrent (84% polyester / 16% elastane) 100% merino wool 51% merino wool/49% recycled polyester seamless zigzag knit comprised of 18.5-micron-gauge lofted wool
Cuts avaliable 1/4 zip, crew, 1/2 zip hoody Crew, 1/2 zip neck 1/4 zip neck Crew, 1/4 zip Crew, hoody
Smelly over time? No No Yes No No
Odor Control Fabric Naturally odor resistant Naturally odor resistant Polygiene Naturally odor resistant Naturally odor resistant
Thumb Loops? No No No No No
UPF (Sun Protection) 50 No N/A No No
Length (short, medium, long) Medium Medium Long Medium Medium
Fit (Based on 5'7, 140-lb woman wearing size small) Fitted (not tight), true to fit. Fitted (not tight), true to fit. Tight and long, true to fit. Fitted (not tight), true to fit. Fitted (not tight), true to fit.
Accessory Pocket? No No Yes (on arm) No No
Flat-lock seams (prevents chaffing) Yes Yes Yes Yes Yes

Our Analysis and Test Results

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.

Performance Comparison


The Smartwool 250 Zip continues to crush the competition. It does exactly what a good base layer should. Keeps you cool when you're hot and warm when you're cool. A perfect layer for any adventure  even cozy cabin ones.
The Smartwool 250 Zip continues to crush the competition. It does exactly what a good base layer should. Keeps you cool when you're hot and warm when you're cool. A perfect layer for any adventure, even cozy cabin ones.

Warmth


Packing in 250-grams of merino wool, this midweight baselayer offers exceptional warmth.


It offers 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.

Cold weather in Northern Canada and Washington State had us testing in temperatures that dipped into the double negatives. Here we test on a lift at Mt. Baker when temperatures hovered just around zero degrees Fahrenheit.
Cold weather in Northern Canada and Washington State had us testing in temperatures that dipped into the double negatives. Here we test on a lift at Mt. Baker when temperatures hovered just around zero degrees Fahrenheit.

This warmth is largely attributed to its warm heat-conducting fibers. On days where we went from hiking really hard to standing still for lunch, we didn't get cold. While the wool itself is incredibly insulating, it is as equally as breathable. During these aerobic events, we sweat. When that happens, if the base layer cannot release the heat, you get cold. This fabric and construction are able to do that really well.

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.

Breathability


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 than other constructions.


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.
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 celebrate 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.

A look at the fit of our Editors' Choice award winner.
A look at the fit of our Editors' Choice award winner.

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.

Layering Ability


Layering can be a small pain with this top, similar to other Merino wool contenders. With a face fabric that features a soft and "grabbier" fabric, we often found it difficult 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 more slippery face fabric.
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 more slippery face fabric.

Durability


Utilizing a 100% Merino wool construction, this contender is the most durable, especially compared to synthetic models we tested. 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. After three years of testing, though, our base layer is still going strong.


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. That said  we've had this model for years  and while it shows some wear  it's still holding up fine and still our favorite all-arounder!
While this top didn't earn any holes, we noticed some pilling around the wrists and some stitching fly-aways. That said, we've had this model for years, and while it shows some wear, it's still holding up fine and still our favorite all-arounder!

Value


While this top is not the most durable, it certainly holds its value with its wonderful comfort and thermoregulation. The top base layers are priced within the same price range, and this is our favorite. If you're going for a long-sleeve merino wool top, we recommend this base layer most readily to our friends.

Conclusion


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. And the next one. And then the one after that.

The Smartwool 250 1/4 Zip is our favorite base layer  offering supreme warmth and comfort through even the coldest of days of winter.
The Smartwool 250 1/4 Zip is our favorite base layer, offering supreme warmth and comfort through even the coldest of days of winter.


Amber King