Think of the shell of your backcountry ski jacket as an extension of your skin. Just like the biggest organ in (or should we say on) the body, your shell has two very important purposes—to keep you dry and to breathe. The problem is that those two objectives are often at odds with each other. Wear a completely waterproof shell and you sweat like a pig, but truly breathable jackets won’t keep out foul weather. Just like your skin, a good backcountry shell needs to adapt to changing conditions, and move sweat away from the body as well as it keeps out precipitation. The secret to that perfect balance of waterproof breathability is the membrane, a porous barrier sandwiched within a shell that won’t let moisture in but will let sweat escape. Now here is an important point: the actual fabric is more than the waterproof/breathable membrane. That membrane is bolstered by the layers that surround it. This combination—the type of fabric and type of membrane—determine what type of performance you get out of a backcountry shell. Now, if all that makes choosing the right shell for you sound confusing, we suggest you look at the balance between how much protection you need, how heavy you want your shell to be and the weather conditions you will be facing. The easiest way to do that is to look at shells according to the fabrics and membranes in them. Our most durable shells, the ones that keep out the worst of the elements yet survive the most abuse, use top-of-the-line GORE-TEX® Pro Shell fabric. Built with input from guides at Canada’s Yamnuska Mountain Adventures, the Mentor Jacket™ needs to repel day-upon-day of nasty weather yet still allow for athletic skinning and climbing. We used Pro Shell fabric here because it’s durable enough to handle rough use and also provides the highest level of waterproofness and protection that pros and hardcore users require. The deal sealer, though, is durability; this jacket will hold up to abuse. Sometimes you want that same protection but require a bit more breathability. So we have created hybrid shells, too. By combining GORE-TEX® Pro with GORE-TEX® fabric in our Furio Jacket™ and Furio Pants™, we put the heavy protection of GORE-TEX® Pro where you need it on the shoulders and side, and use the lighter, airier GORE-TEX® in the rest of the jacket to cut down on weight. For some of our lighter shells, we use Pertex® Shield Plus. It’s a fabric that boasts a durable face fabric—that’s the first layer of your shell, the one that faces the elements—with a waterproof/breathable membrane. It’s also quite light. When the professional guides in our International Federation of Mountain Guides Associations (IFMGA) test team asked for a simpler shell for alpine climbing and backcountry touring, we turned to this material to build the Paladin Jacket™. Their feedback? The lighter fabric moves well during athletic exertion like ice climbing or touring to alpine refuges. The Outdoor Research proprietary Ventia Dry™ and Ventia Hybrid™ waterproof/breathable construction is used in other applications, including in some hybrid jackets, like the Alibi Jacket™ and Alibi Pants™, where we want to meld waterproof protection in key areas, like the shoulders and hood, with soft shell fabric elsewhere for breathability. While engaged in sports like ice climbing, it offers waterproof protection from ice and water falling from above, while leaving other areas of the jacket more breathable so sweat can evaporate. We also use Ventia Dry™ construction in the popular Outdoor Research Mithril Jacket™, which looks and feels like a soft shell but has a full waterproof-breathable laminate, so it’s actually a fully waterproof shell. Then, there are stretch-breathable soft shells, like the Cirque Jacket™ and Cirque Pants™. These fabrics block most wind and light precipitation, but don’t include a waterproof/breathable membrane. The upside to not being waterproof is that they are extremely breathable, so they often work better for high-output activities, especially in dry, cold conditions. Beyond the fabric and membrane, look at the features on a shell. Pick a jacket and/or pants that have the type of pit zips and pockets or even hood style that will serve you best where and when you plan on using the shell.