From cool- to warm-weather adventures.

Whether you're doing some spring skiing or summer camping, the Smartwool Men's Merino 150 Baselayer ensures your activity's done in elevated comfort thanks to the body temp regulating and stink-free properties of merino wool. One of SmartWool's lightest and most versatile base layers, this piece uses Core Spun technology, which wraps the merino wool around a nylon core for added durability without sacrificing the comfort of ultra-soft Merino next to your skin. It also features smooth, flatlock seams for chafe-free performance under the straps of your pack, and is designed to fight off funky odors after a particularly demanding adventure.

  • Baselayer for lightweight performance in cool or warm temps
  • Merino insulates, wicks moisture, and naturally inhibits odor
  • Slim fit clings for top-tier performance
  • Shoulder panels eliminate top shoulder seams for comfort under straps
  • Flatlock seams go easy on your skin
  • Reviews
  • Q & A

Go-to Baselayer

  • Familiarity: I've put it through the wringer
  • Fit: Runs large
  • Size Bought: M

This has become my go-to baselayer. My main activity is hiking.

Just the right weight

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Size Bought: Large

Perfect for slumming around town or going on a run. Has a nice thin feel that works as a layer or by itself without looking too technical. Doesn’t feel like wool as a 250 weight does, more like a T-shirt. Leaves odor behind so you can wear repeatedly without washing even after sweating (not kidding, my wife does not tolerate smells).

Fit & Features

Learn more about the fit, features, and benefits of Smartwool Merino 150 Men's Apparel. #gofarfeelgood


    Fits a bit loose for a base layer but once I wash I'm expecting a touch of shrinkage. Warm, looks nice, and comfy

    All around best base layer

    • Familiarity: I've put it through the wringer
    • Fit: True to size
    • Size Bought: Medium

    This layer is wonderful for all kinds of weather. I have worn it on technical climbs in Alaska and the tetons, as well as backpacking in the summer heat to hide from the sun. It literally works everywhere as a strong versatile base. Super comfortable and fits really well. wicks all moisture and keeps you dry and stink free for days.

    My Go-to base layer

    • Familiarity: I've put it through the wringer

    This thing is on for just about every activity I do in the winter.