Technical rain gear is your backcountry suit of armor: No matter how rainy, snowy, sleety, or windy it gets outside, the right waterproof jacket (and maybe pants, too) will keep you dry. The added protection is nice on a summer day-hike. For any higher-stakes activity, however, from winter excursions to multi-day treks to high-altitude missions, it’s downright essential where wet clothes can be uncomfortable at best and dangerous at worst.
Technical rain jackets (also called shells) are the ones suitable for just those types of trips—think backpacking, mountaineering, skiing, and climbing. There are scores of them on the market, using an alphabet soup of various technologies designed to be both waterproof and breathable. What they all aim to do: keep precipitation out while still allowing sweat vapor to escape, preventing you from getting wet from the inside. But what works for a 14er bid isn’t necessarily the best bet for hiking the Appalachian Trail. Here’s how to sort through the options.
In this article, you’ll learn:
- The technology behind different waterproof/breathable membranes
- The difference between 2-, 2.5-, and 3-layer jackets
- How to evaluate face fabrics for strength, stretch, and eco-friendliness
- What waterproof ratings mean
- How to compare different features
How Membranes Keep You Dry
There are several ways to add water resistance or waterproofness to a shell, but when it comes to technical gear, the best choice is a waterproof/breathable membrane. These delicate, ultrathin films contain countless minuscule pores—too small to allow water to pass through, but large enough to let body heat escape. They’re bonded to a face fabric (the outside of the jacket) for protection and durability, forming a layered material called a laminate. There are quite a few different membranes out there.
The oldest and most recognizable is Gore-Tex, made from expanded polytetrafluoroethylene (ePTFE) and polyurethane that lets sweat from your skin diffuse through. Other brands offer air-permeable membranes, which allow air (but not water) to pass through from both the outside and inside, purportedly increasing breathability (NeoShell, eVent, The North Face’s Futurelight, Outdoor Research’s AscentShell). Yet another choice is a polyurethane (PU) membrane, which is hydrophilic (water loving) and therefore pulls moisture away from your skin. And two technologies—Columbia’s OutDry and Gore-Tex’s Shakedry—dispense with the face fabric and place the membrane itself on the outside of the jacket.
So which one is best? It depends: Any reputable waterproof/breathable membrane will keep water out. Breathability is the big X factor, and it depends a lot on other design choices in a particular garment, such as face fabric, fit, and pocket placement. And don’t forget: The one membrane that can completely keep up with body heat production at peak exertion has yet to be invented—in the worst conditions, you might feel swampy in even the most breathable fabrics available.