Do you alpine climb or backcountry ski and do not own a pair of soft shell pants? If the answer is yes, go buy a pair now. Yes, they are really that essential. That’s why it is very rare to see a professional guide in the mountains without them.
So what exactly are “soft shell” pants? They are an outer-shell pant made from synthetic materials, such as polyester and nylon, and they are NOT waterproof. The fact they are not waterproof is actually why they are so valuable in your quiver of outdoor clothing. They are extremely breathable, highly wind resistant and slightly rain and snow resistant. Being an outer shell layer, they have little to no insulation. This would be in contrast to what is known as a “hard shell’ pant which is waterproof and somewhat breathable. At times the hard shell is an essential layer of clothing, but not nearly as often as you may think.
The reason soft shell fabric breathes so well is the fact that they are not waterproof. What many people do not realize is that the many waterproof/breathable fabrics on the market (such as Gore-tex) may be breathable, but they do not breath well enough for high exertion in the mountains. So what tends to happen with waterproof pants is you get clammy and sometimes downright wet from your own sweat and water vapor not being able to escape quickly enough. This leads to the exact opposite result of why you are wearing your waterproof pants in the first place.
So how do you stay warm and dry with a non-waterproof pant with no insulation? Simple physics is the answer. When you are working hard breaking trail through knee deep snow you are sending lots of moisture out of your body in the form of vapor or sweat. With a soft shell material that vapor is continually being pushed out into the world. While this is happening it is very hard for moisture from the outside to make it inside against the flow of your bodies water vapor escaping, thereby keeping it outside where it belongs. In addition, soft shell materials with no insulation dry very quickly and do not hold moisture much, if at all. If the thin soft shell pant is just not quite enough warmth for the temps you are facing you can then add a layer of long underwear underneath the pant, which doesn’t affect the breathability at all.
There are many different types of soft shell materials on the market. One of the original and still one of the best is the Swiss-made Shoeller fabric used by many clothing manufacturers such as Black Diamond. Other companies, such as Patagonia make their own soft shell material, also excellent. All these materials have at least some stretch in them, another big plus for soft shell pants.
Some examples for skiing would be Black Diamond’s Dawn Patrol Touring Pant and Patagonia’s Dual Point Alpine Pants. For climbing there’s Patagonia’s Alpine Guide Pant and Black Diamond’s B.D.V. Alpine Pant.
There are also hard shell jackets and pullovers which are great layers to own in your quiver but perhaps not as essential as the soft shell pant. Keep in mind that a soft shell layer is one layer in a complete layering system including base layers (long underwear), insulating layers (such as down jackets and fleece) and outer layers.
So should you go out and ditch those bulkier hard shell waterproof breathable pants? No! If you find yourself standing around in a driving rain or in very wet snow, the hard shell pant is absolutely essential. But when you find yourself working hard aerobically in dry, windy or damp weather then yes, ditch the hard shell/long underwear combo for a pair of comfortable soft shells. You can always put the hard shell pant on over the soft shell, but you’ll find you may be doing that less than 20% of the time. Once you own a good quality pair of soft shell pants you’ll find them to be your go-to pant and wonder how you ever managed without them.