The 1-2-3 Guide to Layering
Knowing the function of the layers used in the art of layering informs how you stay comfortable in the outdoors.
You want to be comfortable outdoors, and your layering strategy helps you manage your comfort. When the weather or your activity level changes, you put on or take off layers to regulate your comfort level. For example, if it rains, you put on a rain shell. If you turn off the trail and start climbing, you take off the sweater. Layering provides you options to adapt what you wear to changing conditions.
Here is your by-the-numbers guide to help you understand how layers function in regulating your comfort.
1 - BASE LAYER
The base layer is closest to the skin, so its main job is to keep you comfortable at skin level by retaining warmth and wicking away moisture. Because it is the first layer you put on, the base layer is what you feel against your body regardless of other layer choices. You want it to be, again, comfortable but also functional.
Weather conditions and temperature dictate the choice of lightweight, midweight, or heavyweight options. Fabric options for base layers include synthetics like polyester, spandex, and nylon, and natural fibers like silk, Merino wool, and wool blends. Base-layer tops and bottoms include T-shirts, long-sleeves, tank tops, quarter-zips, and thermal underwear.
2 - MID LAYER
The mid (middle) layer is primarily an insulating layer, one that traps and sustains warmth, with the best mid layers also wicking moisture and reducing odor. Popular materials used in mid layers are the same as the base layers but generally thicker. Mid layers include fleece jackets, sweaters, long-sleeved tops, and even down jackets.
The mid layer is also where you can add layers. Outdoor enthusiasts will often double- or triple-up on mid layers to adjust their comfort in colder weather.
3 – OUTER (SHELL) LAYER
The outer layer is your shield in a battle against weather conditions. Worn over base and mid layers, the outer layer stands against the rain, wind, snow, and wind, and keeps in warmth. The outer layers include hard and soft shells, each offering some level of wind or water resistance.
The categories for wind resistance are windproof and wind resistant. For water resistance, they are waterproof/breathable and water-resistant. Hardshell is typically used to describe waterproof/breathable jackets and pants, and softshell to describe gear that integrates insulation into the shell. An insulated shell — think puffy jacket — is one filled with down or another fill material.