The ideal trail shirt has the stink-free properties of merino wool and the quick-dry properties of synthetic fabric, and that’s how this two-layer long sleeve won us over. The interior polypropylene material helped wick away sweat within minutes and never made us itch, even on a foggy 50°F run in California’s Las Trampas Regional Wilderness Park. Plus, the Lightweight Crew’s 100-percent wool exterior kept us warm down to 35°F and fended off the stench that usually builds up in pure synthetics. Testers praised the cut as well: “So many tech tees are clingy, but this one had a relaxed yet tapered cut,” reports one tester who wore it for 100 miles in New Hampshire’s White Mountains. Lay-flat seams on the shoulders and at the sides prevent rubbing under a heavy pack.