One of the most common questions we come across boils down to fabric, how it works and why it’s important to know the difference. To cover the basics, clothing differs in three ways, performance, fit, and function. Function comes from features on the item like pockets, hoods, zippers, RECCO chips, pass holders, powder skirts, so on and so forth. Fit comes from the design of the piece and generally varies from manufacturer to manufacturer. Lastly, performance comes from the fabrics, or combination of fabrics used to create the garment.
When it comes to active wear clothing, fabric breaks down in two ways. A garment is either made with natural fibers like cotton, wool, and silk, or synthetic fibers like polypropylene, polyester, spandex, lycra, and an array of others. To narrow it down farther, cotton and silk are rarely used these days so when we talk about “natural” fibers in active wear clothing its almost always some form of wool.
Before we get into the advantages and disadvantages to synthetic clothing, lets cover the infrastructure. Synthetic fibers are made in a factory somewhere rather than harvested and spun like natural ones. When you break down the ingredients, they basically equal plastic in some form or another. They can be made from recycled product, which is cool and usually recycled again once they’re used up. In order to achieve maximum functionality, they’re usually coated or treated with some form of a treatment. Often, for wicking they’re given and hydrophobic and hydrophilic treatment to help move moisture. To prevent order and smell they can be infused with silver to help fight bacteria and buildup.
The advantages to synthetic materials make them great for general public use. The material is highly accessible and inexpensive to make which bounces back to the consumer right away so they’re usually less expensive than a wool garment. They also tend to hold up better against direct abrasion from rock, concrete, or chaffing. Synthetic fabric will dry faster than wool. Being that the fibers are essentially some form of plastic they don’t actually absorb moisture, but merely hold it in the pores between the individual strands. This is great for a wet day because once you’ve soaked through the garment you can essentially wring it out. When you combine that trait with a moisture management treatment for wicking, you get a piece that will dry itself in record time.
The disadvantages to synthetics are simple, and for day to day use don’t have much impact. First, they tend to smell. It’s just one of those things that happens, they get musty with use and you just can’t wash that smell out. Second, they don’t discourage sweating. The actual breathability from these garments happens in the pores between the fibers so you’ll find yourself sweating faster in a synthetic piece than a wool one. Lastly, they’ll break down naturally over time. Again, not much you can do about this here, the fibers just tend to degrade after 7 years or so.
Wool is a naturally occurring fiber designed to keep mammals warm, dry and comfortable. That being said, wool is almost always going to outperform a synthetic based garment. Wool fibers are considered to be an “active fiber” meaning that it actually reacts to how your body is feeling. The colder it is the warmer wool will keep you and the warmer it is the more cooling it will feel (within reason). This is due to a number of factors, the largest being the ability for wool to breath. Natural fibers (all of them) allow air and vapor to pass directly through the individual strands so you get optimal breathability all the time. This means that when you’re overheating past the point of sweating and just expelling vapor, that vapor is allowed to pass right through your garment without condensing on a plastic fiber and making you feel wet. This, in turn, keeps you drier no matter what the conditions might be. It prevents hypothermia from damp sweaty clothes in the cold and chaffing from damp sweaty clothes in the heat. This is a really big deal because it generally means you’re going to be more comfortable when wearing a wool garment.
The big disadvantages to wool are simple. First, wool is always going to be more expensive. It’s harder to harvest and turn into a fiber, and it’s a finite material. Second, wool does take a while to dry once it’s fully saturated with water. It will continue to perform and keep you warm, but if you find yourself falling in a lake you’re going to remain damp for a little while. Third, surface durability isn’t great. If you’re a rock climber, or a canyoneering fanatic, or someone who finds themselves rubbing up against things all the time, well you might want to stick to something synthetic.