If you’re like us, the shirt you put on at the trailhead is the same on you’re wearing at trip’s end, even if it’s a week later. So that one shirt better do it all, and do it all well: wick buckets of sweat, dry quickly, fit perfectly, control stink–and look flattering. After testing more than 40 of the latest baselayers, we’ve narrowed the universe down to eight top performers.
Fastest Drying [65–100°F]
ExOfficio ExO Dri (m) / ExO Dri Pointelle (f)
Don’t blink, or you’ll miss seeing this shirt wet. "It was raining off and on all day, and we didn’t have jackets with us," said one tester after a hot hike in Prescott National Forest. "Whenever the drops stopped, my shirt was always the first to dry." The Dri-Release fabric (an 85/15 poly-cotton blend) is designed to suck moisture like a Hoover and transfer it to the shirt’s exterior so it can evaporate more rapidly.
We liked the flatlock stitching and forward shoulder seams, which prevent chafing under a pack. Women raved about the pinprick holes on the Pointelle version, which significantly improve ventilation while adding a touch of style. Although the ExO fabric is chemically treated to resist odor, some testers said they were holding their noses after a few days of heavy sweating in this shirt. Also comes in long-sleeve. $34 (men’s M–XXL), $30 (women’s XS–XL) (800) 644-7303; exofficio.com.
Best Overall Trail Tee [55–100°F]
Icebreaker Tech T Ultralite 140
Wearing a wool T-shirt in the broiling desert is a bad idea, right? Well, after a 15-day spring trip in southern Utah when the mercury pushed above 90°F, our test crew begs to differ. "During the day I stayed cool, even when sweating under a heavy pack," said one tester. "Then at night, when temps dipped to the upper 40s, this shirt kept my core warm with only a wind shell over it."
Despite our testers’ perspiration, this top was surprisingly stink-free at trip’s end. It dried faster than any of the other wool tees we tested – about 20 minutes after being worn in a canyon pool on a hot, sunny day (drying time will be slower in humid climates). Fit is comfortably loose but not baggy. The shirt rebuffed thorny tamarisk and looked new even after a dozen-plus machine washings. $55; men’s S–XXL, women’s XS–XL (208) 726-1000;icebreaker.com.
Dale of Norway Baselayer
Fights nearly broke out when it came time for testers to rotate shirts – nobody wanted to give this one up. "It wicks well, and it’s so soft it practically gives me tingles down my spine,” raved one tester. The reason is Dale’s proprietary blend of Australian and New Zealand ultrafine merino, which after multiple washings didn’t get stiff or scratchy as lesser wools tend to do.
Dale uses no chemicals in the wool washing and dyeing processes, and the antishrink treatment applied to the finished product is also chemical-free. Fit is roomy enough to layer a T-shirt underneath, and an 8-inch zipper on the mock turtleneck allows for venting. One bummer: You can’t put it in the dryer, and some testers said it lost a bit of shape after line drying. $69; men’s S – XXL, women’s S – XL (800) 441-3253; daleofnorway.com.
Most Versatile [50–75°F]
Ibex Woolies Crew
"It’s like there’s a hidden thermostat inside," commented one tester on this top’s outstanding natural temperature regulation. We stayed comfortable across a gamut of conditions, ranging from snow (worn under a shell) to a sunny 70°F. The 100% merino is as smooth and soft as a baby kitten; it wads up small enough to fit in a front pants pocket, yet provides as much warmth as a synthetic fabric twice as thick.
When the mercury rose, testers said the Woolies wicked and breathed like a second skin, and only started to feel hot in the upper 70s. Flat seams and a body-hugging fit make it comfortable under a pack. And thanks to wool’s natural odor resistance, testers on extended backpacking trips reported that their bagels got moldy before their shirts started to stink. Also available in short-sleeved and sleeveless. $60; men’s and women’s S–XL (800) 773-9647; ibex.com.
Sweat Sponge [45–60°F]