Men's Black Baselayer Bottoms

Think about your activity: heavyweight merino is best for static cold pursuits like winter camping, while midweight synthetics excel for sweaty, high-output mountain sports. A 250gsm or heavyweight wool provides extra insulation, whereas Capilene or midweight blends (around 5–7 oz/yd²) dry faster and ventilate better.

Aim for a snug, compressive fit that sits next-to-skin to wick moisture without bunching under layers. Look for full-length legs, gusseted crotches and stretch panels, and use sizing from XS to XXL to find a slim profile that layers well under ski or hiking pants.

Merino wool needs gentler care, so wash on a delicate cycle or hand wash and avoid high heat when drying to preserve fibers. Synthetics like the REI Co-op Midweight Bottoms are more durable and quick-drying, making them easier to launder after frequent use.

You’ll find merino excels at natural odor resistance and regulates temperature across activity levels. Models like the Meriwool 250 Bottoms offer breathability and comfort in ranges roughly between 0°F and 50°F, helping control odor on multi-day outings.

Look for flatlock seams to reduce chafing, reinforced panels and high-denier fabrics for abrasion resistance, plus a gusseted crotch for mobility. These details are common on midweight synthetics and some merino blends, and they lengthen garment life for rough trail or backcountry use.