Choosing what clothing to ski in these days can be quite the difficult proposition given the variety of different fabrics and materials used in today’s technical layer wear. Dependent upon the type of activity and current weather, one’s layering densities and preferable fabric may vary, however the basic system remains the same regardless.
Base layers can be made up of synthetic fibers such as Polypropylene, polyester, wool, or even a blend. All will insulate the body when wet, however each fiber has its own proprietary characteristics that make it desirable for specific activities and uses.
Polypropylene is an engineered synthetic fabric constructed from Low Density Polyethylene (LDPE) that was designed with the specific function of transporting moisture away from the body in mind, thus keeping users dry and capable of maintaining proper core temperature. Therefore, it excels as a base layer fabric for active sports. It is highly functional-yet-affordable, widely available, and also oftentimes comes from a recycled source such as repurposed drink bottles. Downfalls of “polypro” are a propensity toward retaining bad odors, sometimes even after only one particularly active day, and finicky washing/drying requirements, as the fabric can shrink and even melt if temperatures are set too high.
Wool has managed to evolve in recent times with some help from clothing manufacturers and shake the “itchy sweater” association that many remember from years past. “Merino” wool has taken the natural fiber market by storm, offering enthusiasts a wool product that is devoid of itchiness, while also having superior durability and insulation characteristics. Also of note is merino’s unique capability in fighting stench. Unlike polypropylene, it is common to forget about a wool top in a backpack after wearing it on a long ski outing. Then having the ability to pull it out to use it the next time without it needing washing to remove nasty smells. This comes from the presence of a naturally microbial substance called lanolin within the fibers. Taken from the Merino sheep, which is prized as an economically efficient and renewable source of fiber, merino wool is a modern replacement for old world itchy wool. It does, however, come at a premium price compared to its synthetic brethren. Polypropylene tops range in price from about $35-$70. For a similar piece in wool, cost is more likely to be in the $80 to $100 range.
Both wool and polypropylene are offered in a variety of different “weights,” ranging from a silk-like knit that is perfect for high-output activities such as running or Nordic skiing, to expedition weights that will keep users warm even when sitting still on icy chairlifts. The key is to figure out which weight provides the proper balance of transpiration and insulation. An important question is “how much do I sweat during a given activity?” A good guideline is to err on the side of lighter weight when choosing one’s base layer, as other insulating layers can always be added on top, yet going shirtless on a particularly strenuous hike or skin is never recommended.
Base layers are undeniably a huge factor in the system of clothing used to keep people safe in extreme conditions. Making smart and well educated decisions when selecting which type of fiber to use can help ensure a comfortable experience for all!