Your ski shell is your skin when you’re outside in the winter. It’s crucial for temperature regulation, weather protection, comfort, and general happiness. And just like your skin, it should shed water, breathe, and fit you just right.
Types/Best Use: Ski shells, the weather-resistant outer layer that will be your best friend in the winter, come in two types: hard and soft, which suit different climates and different types of skiers.
Hard Shell: Hard shells are waterproof, breathable jackets with laminated membranes built inside the fabric. They’re probably what comes to mind when you picture a ski coat, but fabric technology, and how hard shells are built, has changed a lot in recent years. Hard shells work well in a range of weather conditions, but they shine when it’s stormy. They’re typically more expensive than soft shells.
Soft Shell: Stretchy, breathable soft shells are built using a tightly woven face fabric and a wicking inner fabric. They’re wind resistant and highly breathable, but often not waterproof. They’re good for skiing in climates like Colorado, where it’s predominantly dry, or if you’re someone who is highly aerobic (or just plain sweaty). Common soft shell materials include Polartec Power Shield® Pro and Schoeller Dryskin.
Construction: Shells are built using 2-, 2.5-, or 3-layer construction, all of which involve a face fabric, a membrane, and some sort of liner. Some brands, like Patagonia or Mountain Hardwear have proprietary fabric like H2No® or DryQ Elite, while others construct their shells out of material made by a fabric company, like eVent or GORE-TEX®.
2-Layer Shells: 2-layer shells have a waterproof, breathable membrane bonded to the outer face fabric. Inside of that they have a detached, hanging inner liner, often made of mesh, that protects the membrane from oils from your skin, and from wear. Even though there are three parts, they’re considered 2-layer, because the lining isn’t bonded to the face fabric. They’re typically cheaper than 3-layer shells, but they’re bulkier, less breathable, and heavier, too.
2.5-Layer Shells: Your lightest option for a shell, 2.5-layer shells are made of a face fabric, with a bonded membrane, and an inner coating (the .5 later) that helps protect the membrane from abrasion and the oils and gunk from your body. That inner layer, which often just looks like a raised pattern on the inside of the jacket, provides a lightweight barrier, but it’s often not as durable as a 3-layer shell
3-Layer Shells: The burliest of the shells, 3-layer jackets consist of a membrane bonded between a face fabric and a liner fabric. The liner is sealed to the inside of the membrane, protecting it, and also cutting down on bulk and weight. The lining disperses moisture, which is why 3-layer shells tend to feel less clammy, and guards the membrane from anything that might damage its functionality. 3-layer shells are usually the most expensive.
Face Fabric: The face fabric, which is usually a variation of tightly woven nylon or polyester, is there to protect the delicate membrane from outside abrasion and weather. The face fabric can have a big impact on the weight of the garment.
Membrane: Membranes are the shell’s pores. They diffuse internal moisture, and keep external moisture out. The holes in the membrane have to be big enough to let water vapor out, but small enough to prevent liquid water from seeping in. They’re typically made of Teflon, or polyurethane, which form a microscopic web with vapor sized holes.
Lining Fabric: This is where most of your price and weight variability are going to come from. They range from cheap, brushed mesh in a 2-layer shell, to soft, knit polyester backing in the 3-layer shell.
Waterproof/Breathability: A waterproof, breathable jacket is the holy grail of ski shells, and fabric companies like GORE-Tex and Polartec have invested a lot of time and money making fabric that has both of those properties.
Waterproofing comes from the membrane in the fabric, and/or from a coating that’s applied to the outside of the fabric, both of which inhibit breathability. A fabric’s water resistance is measured in millimeters of water it will hold before it leaks, so a jacket that’s rated 20k waterproof was tested to hold 20,000 mm of water over one square inch of fabric without leaking. Breathability, or how much water is evaporated from the inside of the jacket to the outside, is measured by how many grams of water get pulled through the fabric in 24 hours. For instance fabrics rated as 20k waterproof, evaporated 20,000 grams. Fabrics will be labeled based on their waterproof/breathability ratio, so a jacket that says it’s 20K/20K is waterproof to 20,000mm and breathable at 20,000 grams
DWR Coating: Most shells are treated with an external Durable Water Repellent (DWR) coating to up their waterproof factor. It will wear off with use and washings, but you can re-treat you jacket with a DWR product like Nikwax to give it new life.
Insulation: Soft shell jackets are rarely insulated, but hard shell jackets sometimes have an added inner layer for insulation. That layer will be made of down, synthetic insulation, like Primaloft or fleece. Insulation ups the warmth, but increases the weight, and decreases the versatility of a jacket.
Hood: there are three main styles of hoods: built in, detachable, and rollaway, which fold up in the collar of your jacket. Detachable and rollaway hoods, which give you the option to go hoodless, also add bulk and weight around the neck, and add a potentially leaky seam in an area that gets a lot of exposure.
Pockets: What you need to access quickly will define what you should look for in terms of pockets. Some shells have media and pass pockets, which are convenient for resort days, but unnecessary for backcountry skiing. In a jacket that you’re wearing in the backcountry, look for pockets that you can access with your pack on, and ones that are big enough to stash skins or accessories like goggles and gloves on the fly.
Seams: In a waterproof shell, the seams and zippers have the biggest potential to leak, because they’re essentially a bunch of tiny holes in the fabric. There are three ways that seams are made waterproof: they’re sealed, either fully or critically, by sealing waterproof fabric over the edges of the seams. Fully taped shells have all of the seams sealed, which critically taped ones only have it on the seams that are most exposed to moisture. The third option is welded seams, where instead of being sewn together, the seams are heat bonded. Welded seams are lighter and more fully waterproof, but a jacket with welded seams will be more expensive.
Weight: The weight of the shell depends on the construction, the fabric, and the added details, like Lost weight often comes from the details: welded seams, minimalist zippers, and sewn-in hoods all cut weight, but can make a jacket more expensive.
Back Length: Your jacket should be a little longer in back, so it doesn’t gap when you crunch up into an athletic stance. The extra length will keep snow and rain out, too.
Powder Skirt: Powder skirts keep snow from getting up your jacket and down your pants. They’re often detachable, so if you don’t like the constriction of an attached powder skirt you can zip it out.