A shell jacket keeps you safe from rain and wind. Breathable membrane materials make shell jackets more comfortable than the raincoats of yesteryear. The lightest of shells are made for sports use - they pack down very small and are very light to wear. Middle-of-the-line shells are multifunctional and they can be worn pretty much year round. Our sturdiest shell jackets will serve you even in extreme conditions, whether you're out ice climbing or hauling a sled in a snow storm.
In years gone by it was common for hikers and trekkers to wear a rain coat and rain pants, or a poncho and rain legs in the rain and an entire other set of jacket and pants. Thanks to modern materials, it is now possible to stay comfortable in most conditions wearing shell apparel.
Shell apparel needs to be washed, as the oil and minerals from your skin block the tiny pores, decreasing breathability. Always use a liquid detergent, preferably one made specifically for technical apparel. Never use bleach, or fabric softeners. Do not use the centrifuge. Wash with all zippers and Velcro tabs closed.
After washing it pays off to give your shell a bit of heat treatment: using either a drier or a hair drier, you can reactivate the DWR treatment.