Built for 4 seasons, the men's Smartwool Classic All-Season Merino Base Layer bottoms keep you comfy on snowy days or summer nights under the stars with durable wool-blend fabric and an updated fit.

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When layering for mild-weather adventures, start with the women's Smartwool Classic All-Season Merino base layer bottoms. They're made from lightweight jersey with a supersoft next-to-skin feel.

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A great top for any season, the Smartwool Classic All-Season Merino top wicks moisture and regulates temperature, making it ideal as a fall base layer or a single layer when summer backpacking calls.

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With a form-hugging fit, the Smartwool Classic All-Season Merino Lace long-sleeve tee is a great first layer for high-energy activities—like hiking, jogging or rowing crew—in cool or warm weather.

Underwear TopsBase Layer Tops

With its soft and durable merino wool blend, the men's Smartwool Classic All-Season Merino long-sleeve base layer top is game for any adventure from spring skiing to winter hiking.

Underwear TopsBase Layer Tops

Made from a lightweight jersey, the women's Smartwool Classic All-Season Merino long-sleeve base layer top is just as comfy layered under your ski jacket as it is worn alone for summer backpacking.

Underwear TopsBase Layer Tops

Game for any adventure, any time of year, the men's Smartwool Classic All-Season Merino quarter-zip base layer top is made from a lightweight jersey and built for comfort—even under your pack.

Underwear TopsBase Layer Tops

Designed to be your go-to for warm or cold weather, the women's Smartwool Classic All-Season Merino quarter-zip top features lightweight, soft merino wool with a nylon core for increased durability.

Underwear TopsBase Layer Tops

Made from their lightest-weight jersey and built for comfort, the women's Smartwool Classic All-Season Merino quarter-zip base layer top is game for any adventure, any time of year.

Underwear TopsBase Layer Tops

Made from a lightweight merino wool-blend jersey, the men's Smartwool Classic All-Season Merino T-shirt is built for year-round exploration and consistent comfort—even when wearing a pack.

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Made from lightweight merino wool-blend jersey fabric, the women's Smartwool Classic All-Season Merino T-shirt is built for year-round exploration and comfort.

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Made for year-round adventures, the women's Smartwool Classic All-Season Merino tank top delivers the thermoregulating, breathable powers of merino wool to keep you cool in summer and warm in fall.

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The Smartwool Classic All-Season Plant-Based Dye Merino long-sleeve base layer top's movement-friendly cut and chafe-reducing seams offer comfort, while a plant-based dye creates a one-of-a-kind look.

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Comfy enough for lounging at home, yet stylish enough to wear out and about, the Threads 4 Thought Classic Fleece jogger pants will surely become one of your faves.

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