Most waterproof jackets are treated with a DWR (durable water repellent) finish. This treatment is applied to the exterior of the jacket and works to keep the outer fabric of the jacket from becoming soaked (also known as ‘wetting out’). DWR in a good condition will cause water droplets to bead and roll off, rather than soaking into the outer material. Abrasion from rucksack straps, heavy usage and pollutants all degrade DWR over time.
As well as feeling unpleasant against the skin, a poorly functioning DWR coating can lead to condensation on the inside of your jacket, so if your jacket has become clingy, saggy and water sinks into the outer fabric, it’s time to reproof and refresh the DWR coating. See our waterproof care guide for advice on how to do this.