Gear Nerd: What is DWR?

Right about now you’re probably looking outside wondering “Is it too wet to ride/hike/run/do-favorite-thing-outside? Am I going to get soaked by a spring shower?” The answer is maybe—it depends on your gear. As some brilliant person (almost definitely a New Englander) said, “There’s no such thing as bad weather. Just bad clothing choices.” Thats where DWR—or durable water repellent—and other waterproofing tech comes in. 

To kick off this nerdy endeavor, let’s talk about the architecture of a hardy backcountry-loving rain jacket which, for the sake of this educational endeavor, is a 3-layer masterpiece. This is a highly waterproof, breathable, durable, and lightweight jacket.

On the outside, we have the face layer. This is literally what you see when you’re looking at the jacket and it faces the elements head on like a rain-defying hero. This layer is almost always some sort of synthetic like nylon or polyester. Obviously nylon and polyester aren’t heroes on their own, so this layer is treated with a DWR.

A what? A durable water repellent. DWR is a treatment that allows most precipitation to bead up and roll off. It doesn’t actually block all the water, though, which is key to comfort. We want the face layer to be able to breathe a little bit because it’s key that it keeps water out and lets your sweaty self evaporate too!

READ MORE: 10K, 20K? What Waterproof and Breathability Ratings Really Mean

Sandwiched in the middle is the membrane, and while I think the DWR is pretty sweet technology, the magic is the membrane. This super technical layer has tiny holes that are far too small to let water in, but they are big enough to let water vapor escape into the face layer and out.

And uhm. I’m going to digress for a moment while we’re talking about DWR. Think of DWR like deodorant: It only works when you have enough applied. And it wears off too. Be sure to care for your jacket. You can learn more here.

OK finally, we have a liner. This is what you see when you’re looking at the inside of the jacket and it’s just as important as all the other layers. It’s what protects the magic really. We already know you sweat, but you also put off other biological byproducts that just don’t jive with microscopic holes such as oil, dandruff, etc. To make sure the tiny holes aren’t getting jammed up, most liners are coated with a ridiculously thin layer of polyurethane or oleophobic (oil phobic) protection. This keeps the material against your skin relatively comfortable while letting water and vapor move the way it’s supposed to. Away.

Neat stuff, huh?

Now, we don’t want to confuse you but the world of rain loving jackets is more complex than above. There are 2 and 2.5 layer jackets. Coated jackets. Separate layered jackets. Water resistant jackets. Breathability ratings. And so much more. Your best bet is heading into your local EMS to check out the selection and be sure to let your favorite store guide know what you’re looking for. Stay dry!