Most breathable-waterproof jackets are constructed with a hydrophobic membrane in between fabric layers. The outermost layer, usually a heavy-duty fabric, is merely fabric treated with a durable water repellent (DWR). What most jacket manufacturers won’t tell you is that rough treatment and dirt degrades this waterproofing over time. Eventually, the DWR wears off. After that, the jacket can get waterlogged when it rains.
In this case, the interior fabric is usually something soft and, if the designer is smart, moisture wicking. Unfortunately, with the waterproof membrane preventing it from fully breathing, the inside can become a little clammy when the jacket is wet on the outside. The jacket becomes less comfortable and functional as the DWR wears off. The fabric gets soaked with rain from one side and sweat or body heat from the other.
The other option is a rain slicker of thin but totally waterproof material, like rubber. Generally, that’s what you need if you’re sure you’ll be caught in a deluge. The downside is they’re about as breathable as a plastic bag.
Columbia’s OutDry clothing line offers the best of both worlds. Its waterproof membrane is on the outside of the jacket, so the rainproof-effect is permanent. At a glance, its shine makes it look like the classic rain slicker. But, unlike those old slickers, OutDry Extreme layer remains breathable thanks to microscopic perforations in the membrane. Steamy body heat worked up during a hike can escape, but rain can’t get in. The gear is still lined with a moisture-wicking fabric (Columbia’s Omni-Wick EVAP) to feel comfortable even if you work up a little sweat on a misty morning run, or if you work in a rainforest like Columbia’s testers.
Columbia announced the new line in June of last year, and spent over a year and a half developing and testing OutDry Extreme wear. Their no-nonsense beta-testers hit every continent, even Antarctica. The Portland, Oregon based company takes its rain wear seriously, and the Pacific Northwest can see its fair share of wet weather. If OutDry Extreme gear can do the job through Olympic National Park’s 250-280 inches of rain a year, that’s a good sign.