Fifty years ago, when outdoorsmen and women prepared to go hunting or winter fishing or participate in any other cold-weather outdoor activity, the first thing they did was put on a pair of insulated underwear, also called long johns, as their first layer. Some chose separate shirts and pants, while others preferred one-piece units. Those undergarments were the warmest thing we had available, and if it was going to get really frigid, we wouldn’t think of leaving home without them.

What we didn’t know at the time was that while they were the best we had, they were far from ideal. Most were made of cotton, which lends lots of warmth but also holds moisture quite well. So, if we were a little overdressed on the drive to our hunting spot and started sweating, that dampness would remain with us until our body heat finally dried it out. Consequently, comfort was far from guaranteed. Today we know that “cotton kills.” 

Some stalwart hunters swore by their wool long johns, but many of those people also swore at those same undergarments. Wool clothing back then was notoriously itchy, often leaving the wearer uncomfortable and scratching a lot — movement not conducive to having a big buck come within gun or bow range.

Thankfully, what we didn’t know then, we know now. When participating in cold-weather outdoor activities, the base layer your customer chooses just might be the most important decision of all for staying warm, dry and comfortable, regardless of what Mother Nature has in store. In nearly every outdoor activity you undertake in fall, winter and spring, a good base layer can keep you more comfortable, allowing you to have more fun enjoying the great outdoors. Base layers have come a long way in the last half century, and the products available nowadays keep outdoorsmen and women warmer, drier and more comfortable than ever before. 

However, the wide variety of base layer styles, materials and temperature ratings available can be confusing to both retailers and customers if they don’t understand the terminology and the general idea behind layering. Let’s take a look at what makes modern base layers so good and what kinds of things you should consider when choosing base layers for your retail outlet.

Materials

Many of the most popular base layers today are made of synthetic materials rather than natural materials like cotton or wool. That’s because many synthetic materials, like polyester, have all the traits an outdoor enthusiast is looking for to stay warm in cold conditions.

Most synthetics are warmer than old-fashioned cotton garments. But they also have another thing going for them that makes them even warmer: They have moisture-wicking properties that help keep wearers dry, which in the outdoors nearly always means staying warmer. 

“Wicking” is a fancy word for saying the base layer garment draws sweat away from the wearer’s body and pushes it outward, keeping his or her skin dry. Since the surface area of wicking materials is much greater than that of some natural fabrics like cotton, it is easier for moisture to evaporate from them, leaving you warmer and drier. 

The wicking ability of base layers ranges widely depending on the fabric. Synthetic garments made of a high percentage of polyester mixed with spandex and/or nylon wick the best. At the other end of the spectrum is cotton, which has zero wicking ability. If you sweat when wearing cotton as a base layer, or garments made of a higher percentage of cotton, you likely won’t be dry and comfortable.  

Base layers made of synthetic materials are also tougher and more durable than those made from cotton or other natural fibers. And for hunters worried about masking their scent from deer and other game animals, some base layers made of synthetic materials even add a finish that diminishes odor by slowing the build-up of bacteria on the garments.

Among popular natural materials used in making base layers, merino wool is probably the most common. Merino wool is a natural fiber grown by merino sheep. It’s thinner and softer than regular wool, making it easy to wear next to the skin. 

Unlike the old-fashioned wool garments that some might remember from the past, those made of merino wool have lots of upsides without all the negative aspects. Garments made from it are very soft and don’t cause itchiness or discomfort like wool base garments from decades past. Also, while it likely won’t keep the wearer as dry as polyester would, it does have some wicking qualities — far more than, say, cotton. 

Another natural material used in making base layers is silk, and a good silk undergarment just might be the most comfortable thing you can wear next to your skin when enjoying outdoor endeavors. While not best for hardcore outdoorsmen who will be doing activities involving lots of sweating, cooling, then sweating again, it does at least wick moisture better than cotton. 

Of course, there are still cotton-based garments — most with a blend of polyester or other synthetic fabric — marketed as base layers. Their main benefit is usually in the price, as they are typically less expensive than all-synthetic garments. For cotton-blend base layers, remember that the lower the percentage of cotton and higher the percentage of polyester or other synthetic, the better the garment will perform.

Weight

Base layers are marketed for different activities and conditions based on weight — lightweight, midweight and heavyweight. For lightweight base layers, which are obviously designed for times when temperatures won’t be so cold or the wearer will be doing lots of strenuous activity, thinner is better. They might not provide a good deal of insulation, but if it’s just cool outside, many people will be wearing them more for their wicking ability than their thermal capacity.

Base layers labeled as “midweight” can be used either as a next-to-the-skin first layer or as a second layer in colder weather. They wick well and provide thermal protection in moderately cold conditions.

Base layer garments labeled “heavyweight” are made for extremely cold conditions and are typically much thicker than other base layer garments. Since they are usually worn as a second or third layer, their wicking ability isn’t as important as the ability to help keep you warm when most other hunters have gone inside to sit by the warm fire. 

When discussing base layers, the word “layers” is the key. An active outdoorsman or woman doesn’t simply have to choose a base layer at the beginning of the day and plan on wearing just that layer the rest of the day. If it’s going to be moderately cold, two lightweight layers often serve the wearer better than one midweight layer. That’s because as the day wears on and temperatures heat up, he or she can shed one of the layers, ensuring just the right amount of insulation throughout the day.

The same holds true for heavyweight base layers. If it’s going to be bitter cold all day, a good, heavyweight base layer might be just the ticket. But if the day is going to start out frigid and then warm up to only moderately cold, two midweight layers might serve the wearer better since he or she can shed one or both if needed to stay warm and dry.

Fit

While fit might not sound important to many of your customers, it is actually critical to their comfort since it affects a garment’s ability to insulate and wick. Thus, a properly fitting base layer is going to keep your customer much more comfortable and better able to remain outdoors enjoying whatever his or her chosen activity might be.

Base layers are far from being one-size-fits-all garments. If a hunter’s base layer is oversized and saggy, it’s not going to provide him or her with all the benefits a good-fitting base layer will. That’s also true for undersized base layer garments, which can cut into their arms and legs at the cuff, restrict overall movement and overall be very uncomfortable.

For a base layer — either upper or lower — to wick properly, it needs to lay against the skin in order to pick up moisture. Consequently, the fit needs to be relatively snug. I say “relatively” because being too snug often leads to discomfort, and comfort isn’t a factor that most outdoors enthusiasts want to sacrifice if they don’t have to. 

One exception to wearing a base layer snug against the skin is when a hunter chooses a base layer as his or her only upper garment for a cool-weather hunt. In that case, a looser lightweight base layer top might be more comfortable than a form-fitting one.

Retailer Recommendations

In the end, most retailers of hunting equipment and other outdoor gear should carry a good selection of base layers since they are an integral piece of the puzzle for dressing adequately for cold-weather outdoor activities. While most selections should be made of polyester or other synthetic fibers, it’s not a bad idea to carry a few tops and bottoms in merino wool and even silk. Both have their fans, and there are some hunters who just hate synthetic undergarments.

It’s also wise to carry a good range of sizes in lightweight, midweight and heavyweight base layer garments, both tops and bottoms, as it’s not uncommon for hunters and other outdoorsmen and women to wear one weight garment on top and another weight on bottom for the same outing. If you have them on hand, you’ll likely see base layers become a good seller year round.