What is a DWR and How Does it Work

woman in rain jacket

As its name implies, Durable Water Repellent (or simply DWR) is a treatment applied to the exterior of technical outdoor outerwear and accessories which helps them resist water, therefore improving their performance in wet weather. DWR coatings are most commonly associated with waterproof gear; however, they are routinely found on all types of outerwear and accessories, from thick puffies to superlight shells to other articles like gloves. 

What DWR Does

A DWR coating causes water to bead up and roll off of it, which keeps weather like rain and snow from saturating the exterior of outwear like jackets. 

  • On non-waterproof items, DWR helps them stand up to mild weather like a light rain or mist.
  • On outerwear and accessories with waterproof/breathable membranes like Gore-Tex, DWR prevents them from becoming saturated—a condition known as “wet out”—which can leave users feeling damp and clammy, as well as inhibit breathability. 

How DWR Works

DWR works by making the fibers on the outside of a garment hydrophobic, or, in other words, water repellent. DWR does this by microscopically creating a “spiky” surface—think of the bristles of a brush—which increases surface tension when water comes in contact with it and causes water droplets to band together at the outer edge of the fabric. When a DWR coating is no longer functioning optimally, the water droplets spread out across the surface of the fabric, causing it to soak through. 

Caring for DWR

DWR coatings are not intended to last forever—dirt, oils, sunscreen, and a host of other factors clog and flatten out the “spiky” fibers and hamper their ability to fend off water. Consequently, you need to maintain the DWR treatment on your gear. The easiest way to do so is by washing the item in question with a detergent specifically designed for technical fabrics, like Nikwax Tech Wash, as regular detergents often contain additives that stick to the fabric’s surface and affect its performance. 

Reapplying DWR

If your jacket is still wetting out after washing, all is not lost—DWR is easily reapplied. Nikwax offers a host of wash-in and spray-on products that will breathe new life into your DWR and help keep you dry, comfortable, and smiling.

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Questions? Talk to a gear specialist.