Smartwool Classic Merino Base Layer Bottom Boxed - Black, Size M

Engineered from 100% ZQ-certified Merino wool with an 18.5-micron fiber diameter, these base layer bottoms deliver next-to-skin softness without the itch. The interlock knit fabric weighs 250 g/m², striking the ideal balance between warmth and breathability for cold-weather pursuits.

Overview

The Smartwool Classic Merino Base Layer Bottom is a midweight thermal legging designed for men who demand performance in freezing conditions. The slim fit hugs the body to trap heat efficiently, while flatlock seams eliminate chafing during high-output activities like skiing, hiking, or winter running. Merino-covered elastic at the waistband keeps the garment securely in place without digging in.

What stands out

• 100% Merino wool naturally regulates temperature, wicks moisture, and resists odors—even after multiple wears.
• 18.5-micron fibers are exceptionally fine, ensuring a smooth, non-itchy feel against the skin.
• Flatlock seam construction reduces friction and enhances durability for all-day comfort.
• ZQ certification guarantees ethical sourcing and sustainable farming practices.

Technical details

• Material: 100% Merino wool, 250 g/m² interlock knit
• Fit: Slim, with merino-covered elastic waistband
• Seams: Flatlock for chafe-free movement
• Breathability: High—moisture vapor escapes to prevent overheating
• Odor resistance: Natural antimicrobial properties keep freshness
• Care: Machine wash cold, tumble dry low

Our verdict

A premium base layer that excels in cold, dry conditions. The merino wool performs brilliantly for multi-day adventures, and the slim cut layers effortlessly under shells. Ideal for skiers, hikers, and anyone who values warmth without bulk.