Wear it from your home to the coffee shop and into the mountains! This is a favorite piece that not only performs but looks cute! The Merino wool is super cozy and comfortable…it's just not that durable. Enjoy it throughout the year as a stand-alone piece of as apart of a layered system.
Performance Comparison

The Smartwool 250 Crew is comfortable for wear-all-day (and all-night).
Credit: Amber King
Warmth
As a stand-alone midweight baselayer, this 100% Merino wool top is one of the warmest 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.
Featuring a crew-collar cute, this base layer doesn't provide as much protection, nor does it lock in warmth like the Smartwool Merino 250 ¼ Zip. The face fabric isn't super wind-resistant as a wear-alone piece, thus not offering much warmth in poor weather.
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.
Breathability
Constructed of 100% Merino wool, the Patagonia 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. The fabric also doesn't hold moisture, keeping you warm in cold temperatures when standing still.

Credit: Amber King
Comfort & Fit
Boasting comfort and coziness, our testers couldn't get enough of the soft 100% Merino wool construct. 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 provides great coverage for women of all shapes and sizes. It's true to size and allows sufficient stretch. Super comfortable with a fantastic fit!

A look at the fit of this super comfortable base layer.
Credit: Amber King
Layering Ability
Even though we were able to comfortably wear layers over and under the Smartwool Merino 250 Crew, we found 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 of this, it's not the most layer-able under grabby layers. Though under a jacket with a slippery face fabric it does just fine. In addition, it's easy to add a tank top or small tee.

Layering this Smartwool 250 under a mid layer while skinning up Red Mountain Pass in Colorado.
Credit: Derek Stoddart
Drying Speed
This top is not super quick to dry and does absorb some water. This is attributed to the porous and absorbent nature of the fibers. In our tests, it took about 100 minutes to dry. That said when getting caught in a rainstorm followed by a warm sun, this top did a great job drying out while on the body. That said, given its merino wool construct and its ability to wick and breath, we'd recommend it as a base layer for humid or wet weather. Just avoid wearing it as a stand-alone piece in these conditions.
Durability
We are not impressed with the durability of this top. After a close inspection of the seams and fabric, we found a pilling and stitching fly-aways throughout the shirt after three months of testing. In past reviews and this one, a hole rubbed into the face fabric after three months of use. Unlike any other layer tested, it proves to have pretty poor durability…a deal breaker for some.

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.
Credit: Amber King
Best Applications
As one of the cutest base layers tested, it's a great option to wear out on the town or while hiking in the hills. The cozy and warm fabrics are perfect for all-day wear. The midweight design is built for use as a wear-alone piece in the Fall or Spring or as apart of a layering system for cool to cold days. Just avoid it for highly abrasive sports that could tear the fabric.
Value
We realize that merino wool tops are more expensive and less durable than most synthetics. However, we aren't thrilled that this $105 (retail) 100% Merino wool layer shows serious wear and tear after just three months of use. We love the comfort it provides but there are better options out there for less that feature better durability.
Conclusion
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Smartwool Merino 250 Crew is great for everyday use because of 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.