Whatever you do, don’t call it Underwear. That term oversimplifies what might be the most important piece of your ski wardrobe. Today’s base layers are more sophisticated than ever, with countless fiber, construction, fit and weight options. Other layers can be removed, added or adjusted to accommodate climate changes, but your base layer stays put all day, so finding the right one is crucial. We suggest you invest in a few sets—one for warm, one for cold and one for downright bitter days. Natural fibers such as silk and merino wool (from high-altitude-grazing sheep) are naturally renewable, biodegradable and have exceptional thermal properties. They’re also highly breathable and odor resistant. But they can be delicate, so they can break down quickly. Synthetics—polyester and spandex—stretch without losing their shape, so they stay close to your skin where they may
efficiently wick perspiration. They’re machine washable and highly durable, and they won’t shrink or pill. But synthetics are not generally as breathable as naturals, and they tend to hold odors from moisture and perspiration.
Fabrics Natural fibers offer unsurpassed warmth-to-weight properties, even when wet, while synthetics are superior at transporting moisture. If you perspire a lot, opt for a synthetic blend, but avoid high percentages of nylon, which stretches easily, but doesn’t wick or provide much warmth.
Care All base layers, regardless of their weight or fabric, perform better when clean. Use a sport wash product to ensure a complete rinse. Never use bleach, fabric softeners or irons, which can break down a garment’s thermal properties.
Seams More important than you might think, seam construction and position can affect the comfort and flexibility of a garment. Look for flat or seamless stitching and performance positioning, which places seams strategically to avoid abrasion from back-packs and other layering pieces.
Neckline High necklines protect your skin from the cold and wind, and zippers are handy temperature-control devices in changing conditions. But zippers can be hard to get to under multiple layers. Also be aware of overlapping zippers, which can cause painful chin chafing.