The best way to stay warm is to stay dry, and the best way to stay dry is to layer accordingly to the weather outside. Here’s what to keep in mind when putting together a good clothing kit.

Read our 2012/2013 outerwear reviews right here.

Base Layer

Avoid cotton at all cost! Your first layer should be form fitting, lightweight and comprised of wool or a synthetic such as polyester or polypropylene. Unlike cotton, these materials are fast drying and have microfibers to wick moisture away from your skin. They are available in a variety of weights that you should select based on your activity level and tendency to be warm or cold. A good base layer allows you to move freely and has flat seams to prevent rubbing or chaffing. Investing in a quality base layer is one of the easiest and least expensive ways to improve your comfort.

Mid Layer

A mid layer is the best way to provide insulation, and therefore it’s a rotating piece of the puzzle, depending on temperature and how hard you’re charging. The term “mid layer” can refer to many different types of clothing with varying attributes that can blur the line between an under and outer layer. A traditional mid layer is made of loosely woven fabric such as fleece and worn underneath a shell of some variety. The loose weave allows moisture to pass through and out while holding air in place. It should have a snug fit but not so much that it inhibits any movement.

Softshell jackets can also work well as a mid layer, and this is where the line gets somewhat blurred. The soft, woven fabric of a softshell ranks high in breathability but not quite as well when it comes to waterproofness. This makes it useful as an outer layer when breathability is a priority, such as warm spring days in the park or hiking in the backcountry. However, some are treated with DWR (durable water repellants) to help with water resistance, and fabrics such as Polartec’s NeoShell are emerging with higher waterproof ratings. As technology advances, expect to see softshells with increased waterproofing.

Outer Layer

The fundamental part of any good outerwear is a waterproof and breathable membrane. These two qualities are achieved in tandem by way of tiny pores, smaller than water molecules but larger than vapor molecules, that allow vapor to pass to the outside while preventing water penetration. Ratings of these attributes can come off a little confusing at first but aren’t quite as technical as they seem.

Waterproofing is primarily tested using a vertical column of water. The column is placed on the membrane and filled until it penetrates it. If the column is filled to 15,000 mm before moisture makes it through the membrane, then the waterproof rating will be 15,000 mm or 15K. Breathability tests measure how many grams of vapor can escape the membrane per square meter within a 24-hour period. If 10,000 grams escape, the piece rates at 10,000 g/m2/24hr, or simply 10K. Our ratings are listed with waterproof first and breathability second. In this case, 15K/10K.

These membranes are durable but must be protected to ensure longevity, so a layer of fabric, usually nylon or polyester, is laminated to the outside. This exterior fabric is often treated with a DWR to keep it from soaking up water, which would eliminate the breathability of the underlying membrane. There is no standard by which DWR’s are measured and while there is no reason to say that one company’s proprietary membrane or DWR won’t work, there is something to be said for the millions of dollars spent on R & D by well-known brands in the industry. Be sure not to confuse DWR with the waterproofness of the membrane, and look for both when considering a purchase.

When browsing outerwear you will see 2L (two-layer) and 3L (three-layer) options. The membrane and its outer, protective layer are the meat of a 2L jacket, but the inner membrane must also have some protection. To achieve this, the manufacturer can sew in a simple mesh lining or add a layer of insulation. The protection on a 3L garment comes from a hydrophilic (water-loving) layer that is laminated to the inside of the membrane. This third layer attracts water away from your skin and towards the membrane faster, where it can then pass through to the outside. A layer of insulation on a 2L jacket is not to be confused with 3L, as it isn’t laminated to the membrane. Bottom line: a 2L insulated piece will work great on cold days, with proper insulation, a 2L shell will work well all the time and a 3L shell will work really well all the time.

Once these fabric layers are built, they must be stitched together to form your jacket or pants. This process inevitably results in thousands of tiny holes in a membrane that used to be impervious to water. To remedy this, manufacturers seal these holes with seam tape. Some garments are fully taped and some are “critically” or “strategically” taped, meaning exposed areas, such as the shoulders and hood, are taped, leaving less-exposed areas as they are. You will also see welded seams on some pieces, meaning the seams have been overlapped and sonically welded to completely eliminate holes related to stitching. Critical taping will do you just fine if you’re skiing in the park, but if you plan on spending your time in a wetter climate hunting down the deepest snow you can find, you might want to go the fully taped or welded route.

Conclusion

So, as you can see, the options flourish as you move from simple base layers to varied outerwear. No single setup will work for everybody so take this knowledge, ask around, try different combinations and get your layering dialed in. You’ll be much dryer, warmer and happier when you do.

Read our 2012/2013 outerwear reviews right here.

Freeskier would like to thank skis.com and Polartec’s PR man, Fielding Miller, for their contributions.