A GearTrends® Buying Guide brought to you by The North Face

The key to ensuring you are properly prepared to layer effectively is to select an arsenal of garments that you can put on or take off as weather conditions dictate so that the body's core temperature remains essentially constant. Layering begins with the base layer -- the clothing directly against the skin. The next layers, as many as needed (within reason), are the insulation layers. And finally, the outermost layer is the protective layer, the barrier against moisture and wind.

Understand that in putting together the "ideal layering system," what you will be doing is creating a system that effectively combines elements of breathability, wicking (transporting moisture), rapid drying, insulation, durability, wind-resistance and water-repellence, without adding much weight or impeding freedom of movement, and all with just a few garments. The articles of clothing you choose on a particular day will depend on your intended aerobic level and the anticipated weather conditions.

A good salesperson at your local outdoor specialty store can be invaluable in helping to educate you regarding the choices you can make with the layering options your favorite store is able to provide you.

Understanding the layers

Base Layer
The layer against the skin is, essentially, a second skin that keeps the wearer dry, warm and comfortable. This layer is the workhorse in a moisture-management system, moving moisture through it all day long. It is the first layer you will put on and the last layer you will take off, and unless you are going to run around naked, this is pretty much a non-optional layer.

Thick or thin, special weaves or not, merino wool or synthetic, the primary intent of a base layer is to manage moisture (wick or transport perspiration away from the skin) while adding a degree of insulation. How much insulation you require in this layer will depend on how cold the environment will be coupled with your anticipated level of activity.

In general, base layers are offered in various weights:

1. Lightweight for high-aerobic activity and for use in hot to moderately cool temperatures. In this category, some garments are designed to fit close to the skin for better performance. For hot weather, this lightweight wicking layer often consists of a loose-fitting, more open weave. Yes, sport bras and briefs are part of this layering package.
2. Midweight for optimum versatility, warmth and wicking when backpacking, fly-fishing, skiing, snowshoeing or hunting on the move in colder temperatures.
3. Heavyweight (sometimes called expedition weight) for high warmth when activity or movement is limited and the temperatures are quite frigid.

Mid Layer
In building upon the base layer as needed, the choices begin. The goal here is a familiar one -- provide warmth by creating dead-air space which slows the loss of body heat, as well as continuing to aid in the dissipation of moisture begun by your base layer. Since every person has different insulation requirements depending on body size, weight and fitness level, there is no pat formula for universal comfort.

The options are many. Fibers such as merino wool, wool, fleece, synthetic fill and down fill are all excellent insulators. In general, remember that wool retains its insulating capabilities when wet, but gets heavier. Down is the most efficient insulator for weight to warmth, but must be kept dry. Fleece is probably the most favored in recent years simply because it is lightweight, breathable, compressible, has a soft feel, and still insulates when wet. It also dries much more quickly than any of its natural fiber counterparts.

Like base layers, fleece is also available in three typical weights:

1. Lightweight – aerobic activity when it is cool, not cold.
2. Midweight – intended more for moderate activity in near freezing, but not below freezing temperatures.
3. Heavyweight – designed for use when the activity level is low and the temps are below freezing.

Outer Layer / Protective Shell
Enter the soft shell, or softshell. Though it is not meant to confuse the situation, it often does. Part mid-layer insulation (depending on weight) and part hard shell or storm shell (depending on how much wind and water-resistance it offers), the soft shell manages to blend the needs of both the insulative mid layer and the protective hard shell into one garment. To learn more about buying soft shells, see our How to Buy Softshell guide by clicking here.

If it is maximum protection from the elements you need, then walk over to the storm shell / hard shell department in the store filled with Gore-Tex, proprietary waterproof/breathable coatings and membranes, eVent and more. To learn more about buying hard shells, see our How to Buy Waterproof / Breathable Shells by clicking here.

Quick Layer Tip When It Comes to Shells: Any jacket you buy should be roomy enough that you can wear layers of clothing underneath it and pump air through the jacket's venting opening with your body movements. For general outdoor use, seek a length reaching to about the thigh. The extra inches provide additional protection for the legs and rear end, and the jacket will never gather at the waist or creep up. Jackets designed for more athletic pursuits are cut hip length since the extra inches would prove restricting.

Feature Suggestions For Insulative Layers: For the initial layer or two in the mid-layer realm, many folks prefer pullover garments. But for that final, just-in-case, insulative layer, we recommend full-zip every time. You will find that this allows the maximum versatility in ventilation management and makes the last layer much easier to put on and take off. Try to make sure that all the layers have sufficiently roomy sleeves so you can push them up or slide them down. Decide if you might prefer a zip-T neck if available in the mid layer: They ventilate superbly when open, yet insulate very well when zipped up around the neck. In the outermost mid layer, or in the soft shell layer, a chest pocket is a worthwhile feature too, as this provides a place to tuck a snack, a notebook or sunscreen.