Smartwool Classic Women's Thermal Sweater - 100% Merino Wool, 250 g/m², Slim Fit, Crew Neck, ZQ-Certified, Black

Engineered with a 250 g/m² interlock knit of 100% ZQ-certified Merino wool, this heavyweight base layer delivers exceptional warmth and natural temperature regulation for cold-weather pursuits. Flatlock seams and offset shoulder construction eliminate chafing, while the slim fit and crew neckline provide a sleek, layer-friendly silhouette.

Overview

The Smartwool Classic Women's Thermal Sweater is a premium cold-weather base layer built for skiing, hiking, and everyday winter wear. Its pure Merino wool fabric offers high breathability, natural moisture wicking, and inherent odor resistance, keeping you comfortable during high-output activities and prolonged use. The interlock knit provides a smooth, durable surface that resists pilling and maintains shape.

What stands out

• 100% ZQ-certified Merino wool for ethical sourcing and superior softness
• Heavyweight 250 g/m² fabric rated "Warmest" for extreme cold
• Flatlock seams and offset shoulder seams prevent irritation under pack straps
• Natural UPF 50+ sun protection without chemical treatments
• Machine washable for easy care despite premium wool construction

Technical details

• Material: 100% Merino wool (ZQ-certified)
• Fabric weight: 250 g/m²
• Fit: Slim fit
• Neckline: Crew neck
• Sleeve type: Long sleeve
• Seam construction: Flatlock seams
• Thermal rating: Warmest (heavyweight base layer)
• Moisture wicking: Yes
• Odor resistance: Natural
• Breathability: High
• Temperature regulation: Yes
• UV protection: Natural UPF 50+
• Care: Machine wash cold, gentle cycle; tumble dry low

Our verdict

A versatile and reliable thermal layer that combines technical performance with all-day comfort. The ZQ-certified Merino wool offers a perfect balance of warmth, breathability, and odor control, making it an excellent choice for winter athletes and outdoor enthusiasts.