Best overallThe shirt you wear for eight days without anyone minding
Icebreaker Merino 200 Oasis Long Sleeve Crew
Merino at 200-weight is the one true trekking base layer — warm damp, warm dry, and it does not smell; it is also three times the price of synthetic and it will eventually hole at the shoulder where the pack rubs.
Skip it ifA four-day trek where you can wash and change. Synthetic is cheaper, tougher and dries faster; merino earns its price on long trips without laundry.


