Smartwool Classic Merino Base Layer LS Boxed - Fern Green XXL

On a crisp morning at the trailhead, you pull on the Smartwool Classic Merino Base Layer LS Boxed in Fern Green. The 100% ZQ-certified Merino wool feels soft against your skin, and as you start your hike, it begins regulating your temperature naturally. The slim fit and flatlock seams mean no chafing under your pack, while the interlock knit provides a smooth, breathable layer that moves with you.

Key specifications

• Material: 100% ZQ-Certified Merino Wool
• Fabric weight: 250 g/m²
• Fit: Slim
• Sleeve length: Long
• Neckline: Crew neck
• Color: Fern Green
• Size: XXL
• Seam construction: Flatlock seams
• Temperature regulation: Yes (natural)
• Moisture wicking: Yes
• Odor resistance: Natural
• Breathability: High
• Fabric construction: Interlock knit
• Care: Machine wash cold, gentle cycle; tumble dry low
• Sustainability: ZQ-Certified Merino Wool

Why choose it

Merino wool is nature's performance fabric. It keeps you warm when it's cold and cool when it's hot, wicks moisture away from your skin, and resists odors naturally—so you can wear it multiple times between washes. The ZQ certification ensures ethical farming and environmental responsibility. The slim fit layers easily under midlayers and shells without bulk, and flatlock seams prevent irritation during high-output activities.

Ideal use cases

• Skiing and snowboarding as a base layer
• Hiking and backpacking in cool to cold conditions
• Everyday wear in cold weather
• Travel due to odor resistance and packability

Good to know

Machine wash cold on gentle cycle and tumble dry low to maintain the integrity of the Merino wool fibers. Avoid fabric softeners and bleach. The interlock knit provides durability and a smooth hand feel, while the natural breathability keeps you comfortable across a wide range of temperatures.