Classic Thermal Merino Base Layer 1/4 Zip

This is the 250 g/m2 interlock knit that most heavyweight merino base layers get measured against, and the construction is why: flatlock seams that don't chafe under a hipbelt, shoulder panels placed for pack straps, and a quarter zip that lets you dump heat without stopping to strip layers. If you hike in genuinely cold weather, or you run cold in camp, it works as both base layer and standalone midlayer. The problem is that 411 grams is a lot of shirt. At 250 weight it is too warm for anything but cold, low-output days, and if you start climbing in it above freezing you will sweat through and then wait hours for merino this thick to dry. It is also a premium price for one garment, and wool this soft thins at the elbows and pack-strap contact points faster than a synthetic would. Skip it if your cold season is mild or you prefer stacking thin layers.