Men's Aspect Midweight Merino Wool Base Layer Long Sleeve Shirt
An endlessly versatile base layer shirt
Description
As Wirecutter's top pick for the best thermal underwear, the Aspect Base Layer Long Sleeve Shirt is "a city-to-trail shirt" and their "most versatile pick." They capture what we love most about this base layer—it's incredibly versatile, incredibly comfortable and works well no matter where the day takes you. It feels great on your skin and keeps you warm, dry and comfortable, plus it has industry-leading durability. It's cut long to stay tucked in when skiing, and it has discreet thumb holes to keep your sleeves in place. Pair this shirt with the Aspect bottoms in full length or 3/4 length.
Our fall 2026 colors are RWS certified – see more under Fabric Details.
Product Features
- Versatile midweight base layer that's warm but not too warm
- Natural, sustainable Merino wool reinforced with (m)Force Technology for increased durability, dry times and recovery
- Odor resistant, moisture wicking, sun protective, breathable and temperature regulating
- Woolmark-certified Wool Rich Blend
- Backpack-friendly raglan construction
- Discreet thumb holes that keep sleeves in place when needed
- Long cut that stays tucked in when layering
- Low-profile flatlock seams
- Printed neck label & removable care label
- Size M weight: 8.3oz
Fabric Details
Sailor Blue, Fern, Sun Orange/Cinnamon, Black (M-XXL):
- 84% RWS Certified Merino Wool (TE-00339331), 16% nylon
- 180 GSM fabric weight
- Super soft 18.5M Merino wool
- (m)Force™ technology
Black (S):
- 84% Merino wool, 16% nylon
- 180 GSM fabric weight
- Super soft 18.5M Merino wool
- (m)Force™ technology
Care: Machine wash on cold, hang dry, do not bleach or dry clean, iron on low wool setting. Learn more.
Sizing/Fit
- Fits close to the body
- Extra length for more coverage
Not sure what size to order? See our size guide.