Smartwool Merino 150 Crew - Women's Review

The Smartwool Merino 150 is one of our favorite lightweight base layer tops. It performs all-year-round with its impeccable breathability and thin fabric construction. If you run hot or plan on doing the most aerobic sports in the winter, this lightweight contender is an award winner. It is durable, integrating nylon into its merino wool construction.

Performance Comparison

The Smartwool Merino 150 Crew top is a lightweight base layer that specializes in providing minimal warmth and excellent breathability. Wear it on its own in the warm months or with warm layers in the winter.

Photo: Amber King

Warmth

Constructed of 150-grams of blended synthetic materials and merino wool, this top offers little in the way of insulation. It's a great layer for hiking or running in cool weather. However, when temperatures plummet into the single digits, it works best in a warm and insulating layered system.

Built to breathe, it is constructed of super thin fabrics that do best when off-loading moisture and heat. When you put it on in the morning, the merino wool fabric feels cool against the skin and maintains its coolness. When we wore it walking around town on a cold day, we felt cold without an additional insulation layer. This is most likely due to the synthetic fibers integrated into its construction.

This layer is perfect during the first snowfall in October. It provides just enough warmth to keep us comfortable, but cool enough so we don't sweat, even when running up snowy slopes.

Photo: Amber King

However, for high output activities like running or backcountry skiing, it's excellent. Unlike midweight tops, its sole purpose is to wick away moisture, without added insulation. Wearing it on its own in single-digit weather will leave you very cold and shouldn't be attempted.

The lightweight fabric is super thin with very little insulation. While it breathes well, it lacks incredible warmth for cold days.

Photo: Amber King

Overall, this layer can provide you warmth during super cold weather when layered with very warm fleece and jacket. It'll provide all the warmth you need if you're running in the winter or hiking in cold weather. Just be sure to bring a shell. On its own, it's good for warmer days during the Spring or Fall. It's a little too warm for the summer due to its high density of woven merino wool. We generally recommend short sleeves in the summer, though, so this is no surprise.

If you're at the resort you'll find yourself moving then sitting. This layer is great to keep moisture off your skin, but be sure to layer up with a super warm jacket and fleece with ventilation for optimal performance.

Photo: Amber King

Breathability

This lightweight merino layer is wildly breathable and dries very quickly. It'll wick away moisture well without absorbing it in the fabric. This is a wonderful top to wear under a heavy layer of insulation or on its own during aerobic explorations.

An extremely breathable merino wool layer! The fabric doesn't hold any moisture, keeping you dry through the most strenuous activities.

Photo: Amber King

We took it on a few runs in the San Juan Mountains. During a few of these runs, the snow fell, and the sun was out. Our run took us over many hills that provided many sweat-inspiring, try-hard experiences. Even though we sweat, the top kept up dry, even when doing sprint laps uphill.

In a layered system, it functions extremely well as a naturally wicking layer. It's commonly seen amongst backcountry skiers or split boarders who spend a lot of time hiking uphill and sweating profusely, especially on sunny days. With very little insulation, it wicks moisture away from the skin and transfers it to the next layer. It's important to note that if your next layer doesn't have ventilation (like a zip neck) or isn't breathable, moisture can still build up in your layered system. Make sure your whole system has some form of ventilation or breathable layer to provides escape for moisture.

On a fall day, we wear the base layer underneath a fleece layer during a cool summit in Red Rocks Nevada. It offers perfect thermoregulation, even when we are sweating about 800-ft in the air.

Photo: Amber King

In these cases, we are surprised at how quickly the fabric dries when we finally did open up our jacket. While the merino wool did absorb some water with this lack of ventilation (like all fabrics do), we didn't feel cold or wet like we did with other thicker layers that have higher absorption. The result? This is one super breathable layer that wicks away moisture efficiently.

Comfort & Fit

While this top isn't the coziest, it offers great all-day wear. Those that are sensitive to wool might find it to be a little itchy, especially if you manage to build up a sweat in it. The fit is tight, slim, and a little short in the torso, so make sure you size up if you like a looser fit.

This top stays in place, even when putting your arms up in the air.

Photo: Amber King

Midweight tops do better in this metric, and it is no surprise that this award-winning lightweight contender doesn't do as well with this kind of competition. While it is constructed of merino wool, the material is thin and far from plush. There are no super cozy elements like really long arms to wrap your hands into or super stretchy fabrics.

A look at the fit. The length in the arms aren't super long, so longer limbed woman may find this to be a bit short.

Photo: Amber King

While most of our testers liked the way the fabrics feel on the skin, some women that tested this top were more sensitive to wool. Merino wool is renowned for it's "no itch" construction, and for most ladies, this shirt will feel just fine. However, for the more sensitive, you might think it has a tiny itch to it. The reasons are because the knit on this fabric is very tight and more abrasive than the plusher fabrics used in the midweight version of this top. In addition, integrated synthetic fibers are more rigid, which can be a bit more irritating. So if you're especially sensitive to wool fabrics, this may not be for you. Though for those that wear merino wool all the time, you probably find it thin, comfortable, and nice to wear.

A look at the fit of the Smartwool 150. This is on a 5'7" female who is 145 lbs. This is a size small.

Photo: Amber King

Layering Ability

This thin base layer is incredibly easy to layer under and over other pieces of clothing.

Bulkier base layers with "grabby" face fabrics tend to be harder to layer. Given the super thin construction and very tightly knit face fabric, this top is neither. The fabric offers some stretch (but not too much), so it doesn't stretch with a tighter fitting fleece to fit ontop. The whole top is tightly fitted, so it doesn't bunch in the arms or around the torso either. We noticed that because the shirt is a little shorter, it can ride up when worn with other "grabbier" mid-layers. Aside from that, it works just fine.

Here we layer the Smartwool 150 (author in the front) on this warm day in Ontario on the lake. It layers nicely under this tighter, fleecy mid-layer.

Photo: Amber King

Durability

We've only had the pleasure of testing this piece for a couple of months, so we haven't had too much time to detail its entire lifespan. However, looking at online reviews, it has a very good track record. Built with synthetic fibers in conjunction with soft merino wool, it's more durable than other Smartwool products we've tested.

Moving uphill with a tight running pack that is fully loaded is a great way to test abrasion resistance. We love that this lightweight layer is strongly constructed with great durability all around.

Photo: Amber King

While the fabric is thinner, the fabric is packed in such a way that it doesn't snag or grab when being dragged through a forest or pushed up against rocks. When carrying a backpack and running pack, we haven't seen any signs of durability issues. We've washed it a dozen times, and it doesn't shrink, nor has it pilled up.

The only thing we've noticed is some stitching that's come undone around the wrist. Given the thinner construction, we imagine this won't last as long as other synthetic contenders, but time will tell as we continue to test it into the upcoming year.

Value

The price on this base layer top is fair. Those that see the most value in it will be those who need a protective layer in the summer and a wicking layer for aerobic activities in the winter. The durability of this piece seems decent so far.

Conclusion

The Smartwool Merino 150 Crew comes highly recommended for those that push it through all the seasons. Its thinner fabrics are surprisingly durable with great breathability. In the winter, wear it with an insulating mid-layer or jacket to stay warm on the ski hill. In the warmer months, wear it on its own while tackling any adventure during cool weather.

Take this lightweight contender camping in the Fall or skiing in the winter. It offers exceptional versatility. For those that prefer a lightweight to a midweight construction, this is the layer to buy.

Photo: Amber King