Base Layers and Underwear
The best base layers and underwear, reviewed and curated by the Trailspace community. The latest review was added on March 3, 2021. Stores' prices and availability are updated daily.













































Recent Base Layer Reviews

Helly Hansen HH LIFA Stripe Crew
A classic go-to for late autumn-winter-early spring. Tough as nails and a very practical change from wool and other fibres. My “cold weather” (similar to Lester’s) version is now 10 years old and doesn’t show any signs of giving up the ghost. I will say it’s comparable to wool. Not the same AS wool but if you can find a man-made fibre shirt that is known around the world for its quality and practicality, and durability then please let everyone know. When humping a pack, I tend to wear… Full review

Helly Hansen HH LIFA Stripe Crew
An all-time classic design. Form meets function. Every competing manufacturer has tried to persuade the public that the original HH vest is outmoded. It has no zips, pockets, or gimmicks, it isn't made of a new wonder material or rediscovered 'smart' wool. The look is like something from an '80s magazine. So why do they still get made—and sold all over the world—in large quantities? Warmth and wicking. The Lifa polypropylene meets both criteria, when your body is working near maximum and the… Full review

FORLOH Deep Space Half Zip Long Sleeve Top
An impressive, USA-made quarter-zip synthetic baselayer that somehow doesn't get stinky, even after sweaty hikes in the mountains. With excellent moisture-wicking properties and an athletic feel, this baselayer is comfortable and ready to go on all-day adventures in the autumn or winter. While the camo-pattern is targeted toward hunters, it appears the company will be releasing solid color options too, making it more appealing to non-hunting pursuits like hiking, backpacking, skiing, snowshoeing,… Full review

Bight Gear Solstice Graphene Hoody
Very protective, good fit, light weight, and reasonably priced. This is my second sun hoody after the Black Diamond Alpenglow, which I liked. The Bight Solstice Hoody has a better fit for me (not quite as loose) and the fabric is lighter in weight and has a nicer hand. In contrast to the Alpenglow, it has thumb holes which provide a bit more sun protection for the back of the hands without interfering with dexterity, plus it's a bit less expensive ($69) than the Alpenglow ($85 retail). I treated… Full review

Voormi River Run Hoodie
Who needs another baselayer or hoodie? Apparently I do. After three months of use the Voormi River Run Hoodie has become a standout in my baselayer collection. It's a versatile, lightweight, wool-polyester top that is comfortable, well-constructed, good-looking, and odor-free. While it's a minimalist design, it performs in a wide range of temps and terrain—from summer hiking to fall camping, and I'm planning to keep it in rotation for winter runs and skis. Women's Voormi River Run Hoodie I have… Full review

Patagonia Capilene Thermal Weight Zip-Neck
Uncomfortable fabric, poor fit. Worst Patagonia purchase in 35 years. Worst Patagonia item I have ever purchased. Fabric is uncomfortable on the skin. This weight is what came up when I wanted to replace my expedition weight zip top. Ridiculous. This is flimsy, textured on the inner surface. Shoulder area and neck fit is loose and loaded with excess fabric. If I could give it a negative star rating, I would. Full review

Smartwool Merino 150 Pocket Tee
The Smartwool Merino 150 Pocket Tee is an active wear, base layer made up of 87% merino wool and 13% polyester. The high wool content maximizes one of nature's greatest insulator's ability to regulate temperature, ward off the multi-day stink, and manage moisture, while the polyester content adds durability and comfort. A lightweight wool tee allows for an endless amount of uses—from a thin sun shirt on hot summer days, to an excellent next to skin layer as part of a clothing system in winter. Full review

Appalachian Gear Company All-Paca Crew
The All-Paca Crew is a lightweight, medium thickness base-layer suitable for active wear or just lounging around the house during a lock-down. It's made from 100 percent Alpaca fiber. It fills my niche as a three-season hiking/sleep layer, to be paired with a t-shirt on cold mornings and with a shell when the wind or rain begins to cut. It offers a good warmth-to-weight ratio, breathability, and also a hefty resistance to odor. It closely matches the performance of similar technical base-layers… Full review

Smartwool Merino Sport 150 Hidden Pocket Tech Tee
The Smartwool Merino Sport 150 Hidden Pocket Tech Tee is a lightweight tee-shirt, made from a comfortably soft blend of merino wool and polyester (56% merino/44% polyester). This combination makes for a shirt that breathes well, stays cool, dries quickly, and doesn’t stink after a day of hiking. An ideal shirt for warm weather adventures. Unfortunately, the hidden pocket isn't very practical. Conditions: I’ve worn the Smartwool Merino Sport 150 Hidden Pocket Tech Tee regularly for two months,… Full review