A version of this story appeared in the winter 2020 issue of Uncommon Path.
A layering system tends to incorporate three pieces: a base layer, a mid layer and an outer layer. Worn closest to your skin, the base layer should have a snug fit; it wicks perspiration away from your body to prevent your core temp from cooling. Next, the mid layer acts as your insulation, or your warming item. Last, the outer layer blocks wind, rain and snow. Use this guide to create the perfect layering system for your winter activity.
Ice fishing, belaying, hunting in a blind, an easy walk around the block
Merino wool has one of the best warmth ranges of any fabric, thanks to the natural crimp (or zigzag) of its fibers. It traps air in tiny pockets, which warms up fast from body heat.
Synthetic fleece is usually made of polyester. It’s highly breathable and dries fast, and because it typically isn’t bulky, you can easily slide it between other layers.
Down is the fluffy stuff between the bird’s body and feathers. It creates tons of pockets of air (an ounce of down can have as many as 2 million filaments) for the best warmth-to-weight ratio when it’s dry. (It loses loft when wet.)
Resort skiing, building a snowman, a moderately paced walk
Body-mapped base layers use a construction that places different weights of fabric across the garment. Heavier materials go where you require more insulation, like your torso, while lighter materials go where you sweat, like your back and underarms.
Synthetic insulation is composed of man-made threads that are spin to create pockets of air, mimicking down. It’s not as compressible as down, but it’s warm when wet, dries quickly and is usually less expensive.
Waterproof/breathable shells (like GORE-TEX) often use a three-layer sandwich: The interior liner wicks sweat off your skin through a membrane, and the face fabric repels moisture.
Snowshoeing, backcountry skiing, fat-biking, ice climbing, a snowball fight
Synthetic base layers are often lighter and more breathable than wool, making them great at wicking sweat from your skin and drying quickly. But they aren’t as resistant to body odor.
Hybrid mid layers take the best of your base and mid layers to create breathable insulation. Typically, down or synthetic insulation is used around your core, while the remaining areas are constructed with thinner, more breathable fabrics.
Performance waterproof/breathable shells let sweat escape and repel moisture. This one uses GORE-TEX C-KNIT, a three-layer sandwich with a more breathable and stretchy internal liner.
Running, cross-country skiing, any cardio workout
Nylon is highly abrasion-resistant and strong enough to be worn alone (unlike a base layer). Its fibers have solid elastic-recovery behavior and wick sweat.
Ultra-breathable synthetics, like Capilene from Patagonia, sacrifice heat retention in the name of breathability, wicking and quick-drying capabilities.
Polyester on its own isn’t waterproof (and barely water-resistant), but it excels at blocking wind while allowing sweat vapor to escape. Plus, it’s light enough for cardio activities.