Merino for stink and cold-wet. Synthetic for durability and drying speed on humid short trips.

What weight of merino for winter?

260–400 gsm layered under a wind shell. Two 200 gsm layers can outperform a single 400 gsm shirt when you need to vent.

Buying guide

Wool and cold-weather layers buyer's guide

Wool and cold-weather layers include merino base layers, mid-weight wool shirts, boiled-wool sweaters, and wool blankets — insulation you can rely on when wet.

Browse all base layers, underwear & socks See the ranked list

By Wild10 Editors · Fieldcraft desk · Updated 7/16/2026

What we mean by this category

Wool and cold-weather layers include merino base layers, mid-weight wool shirts, boiled-wool sweaters, and wool blankets — insulation you can rely on when wet.

Who this equipment is for

Winter campers, hunters, canoeists, and cold-region travellers who value warmth-when-wet and odor resistance over ultralight numbers.

Important buying criteria

Fiber weight (gsm)
150 gsm for aerobic use; 200–260 gsm for daily wear; 400+ gsm for stationary cold.
Blend
100% merino for max odor control; nylon blends for durability at seat and elbows.
Cut
Trim through the torso for base layers; roomy through the shoulders for mid-weight shirts.
Origin
Traceable wool (RWS, ZQ) usually correlates with better fiber consistency.

Use-case decision table

Activity level	Weight	Best fiber	Layer role
Aerobic (running, skiing)	150 gsm merino	Fine merino 17.5 µm	Base
Backpacking / hiking	200 gsm merino	Blend with 12% nylon	Base / mid
Winter camping (stationary)	400 gsm boiled wool	Coarser merino / lambswool	Mid / insulation
Bushcraft around fire	Wool blanket / anorak	100% wool	Outer insulator

Material or technology comparison

Fabric	Warmth-when-wet	Odor resistance	Durability	Weight
Merino wool	Excellent	Excellent	Fair	Medium
Wool/nylon blend	Excellent	Very good	Good	Medium
Boiled wool (Loden)	Excellent	Excellent	Excellent	Heavy
Synthetic polyester fleece	Good	Poor	Good	Light

Climate and season considerations

In humid cold (Pacific NW, coastal Canada), wool outperforms synthetics because it holds warmth without needing to fully dry. In dry cold (interior mountains, Arctic), a wool base + synthetic puffy is the light system.

Size, fit, or capacity guidance

Base layers should feel like a second skin; too loose and they lose warmth. Mid-weight shirts should stack over a base without binding at the armpits.

Editorial picks

Best overall merino base layer