Merino.tech 165 Merino Wool Base Layer Pants, 100% Merino, 17.5 Micron

Cold-weather clothing can prioritize insulation or a lighter layer that fits beneath everyday pants. These merino wool base layer pants are designed for the second approach, with several fabric weights to suit different conditions.

Need warmth for a hike or outdoor work without adding a bulky layer? The close-to-skin design makes these long johns practical under jeans, hiking pants, or ski pants.

Made from 100% superfine 17.5-micron merino wool, they combine moisture-wicking and odor-resistant properties with options from lightweight to heavyweight.

Highlights

Choose from lightweight 165 g/m², midweight 250 g/m², or heavyweight 320 g/m² fabric. The range makes it easier to match the base layer to the outing: a lighter option for layering under everyday clothes, or a heavier one for colder winter activities. Midweight fabric is described as naturally regulating body temperature for comfort throughout the year.

The superfine merino wool is designed for comfortable all-day wear, while its natural moisture-wicking and odor-resistant properties help keep the layer suitable for extended outdoor use. Rather than relying on a heavier outer layer alone, wearing thermal pants underneath adds a dedicated layer of wool close to the skin. They can be used for hiking, skiing, winter outings, or outdoor work.

Customer feedback often highlights warmth without a heavy feel, and the ability to wear the pants under jeans or hiking pants. Fit and durability feedback is mixed: some buyers find the sizing as expected and report that the pants hold up, while others describe a roomier fit or faster wear. These are useful considerations when choosing a size and planning regular use.

Best use cases

These long johns suit cold-weather layering when you want wool next to the skin without the bulk of wearing another full pair of pants over your clothes. Wear them under hiking pants for a trail outing, beneath ski pants for snow activities, or under everyday pants during winter outdoor work. For less demanding conditions or a closer-fitting layer, consider the lightweight option, for added fabric weight, choose midweight or heavyweight according to the conditions and the rest of your clothing.

How to use it

Wear the pants as a base layer beneath your outer pants, choosing the fabric weight that suits the activity and conditions. The range includes three weights, so the same basic layering approach can work for a light cold-weather outing or a colder winter day. A fitted base layer keeps the wool layer positioned underneath your clothing rather than replacing your outer pants.

The pants are washer- and dryer-safe for straightforward care. To help preserve them for longer wear, hand wash and air dry. Following that gentler care guidance is a practical choice if you expect to use the layer repeatedly for hiking, skiing, or everyday winter wear.

Final verdict

Merino.tech’s merino wool base layer pants are a practical choice for men who want wool insulation beneath their regular outdoor or everyday pants. The 100% superfine merino construction, moisture-wicking and odor-resistant properties, and choice of three fabric weights make them adaptable to different winter layering needs. Choose the weight that fits your planned use, then wear them as a comfortable foundation for hiking, skiing, outdoor work, or cold-weather days.