Smartwool Classic Thermal Merino Base Layer Crew Boxed - Black, Size XL

Experience unparalleled comfort and performance with the Smartwool Classic Thermal Merino Base Layer Crew. Crafted from 100% ZQ-certified Merino wool, this base layer offers exceptional temperature regulation, moisture-wicking, and natural odor resistance, making it the perfect foundation for cold-weather activities. The interlock knit construction provides durability and a soft, non-itch feel against the skin. With a slim fit, crew neck, and long sleeves, it layers seamlessly under any mid-layer or outerwear. Flatlock seams reduce chafing, while the UPF 50+ rating adds sun protection. Ideal for winter sports, hiking, or everyday wear, this base layer keeps you warm, dry, and comfortable all day.

Advantages

Superior thermal insulation and breathability ensure optimal comfort in varying conditions. The natural merino wool fiber is renewable, biodegradable, and offers excellent moisture management. Flatlock seams prevent irritation, and the slim fit allows for easy layering. Machine washable for easy care.

Suitable for

• Cold weather layering
• Winter sports (skiing, snowboarding)
• Hiking and backpacking
• Everyday casual wear

Key specifications

• Material: 100% Merino Wool
• Fabric Weight: 250 g/m²
• Fit: Slim
• Neckline: Crew Neck
• Sleeve Length: Long Sleeve
• Seams: Flatlock
• UPF Rating: 50+
• Care: Machine wash warm, gentle cycle, tumble dry low

Recommendations

For maximum performance, pair with a Smartwool mid-layer and outer shell. Choose your usual size for a snug fit; if between sizes, size up for a more relaxed layering option.