We’ve turned a corner in technically advanced, lightweight down jackets: They are the modern sweater. Upholstered in some modern isotope of ripstop polyester, they look puffy on the outside, but feel incredibly light while on. Such jackets are now thin enough to wear under a coat, pack into a small stuffsack for easy travel, and are comfortable to wear fishing, on the sidelines of a soccer game, or just kicking around the house.
This final feature I discovered through experience last spring, when I moved into a new office heated only by woodstove. Often too lazy to stoke the fire, I simply lived in the coat for days on end. Goose down is still is the world’s most efficient insulator—these light, fluffy feathers underneath the outward plumage of a goose hold the most dead air. And because the down is now packaged in modern science’s softest, most advanced materials, these newer coats are more like a comfortable cashmere sweater. I’ll admit, I’ve slept in it more than once.
Down is a great insulator, but it's usually too hot for aerobic sports. When nordic skiing in the coldest temperatures or hard climbing, a layered approach with synthetic materials often works best because the materials can adapt to your changing body temperatures, and you can shed layers for comfort. Down is for times when you need to stop moving and stay warm, such as sitting on the chairlift, or hoisting a climbing partner on a belay line.
With the advent of ultra-lightweight jackets, there's an even wider range of occasions to wear down. The following are our picks for the best new jackets in this class. All weigh around 20 ounces or less, and several come with a thin polyester bag for safe and compact storage.