March 31, 2020 2 min read

If you’ve been clicking around our site, you may have noticed DWR listed in the specs of our blankets. But what is DWR, and why is it so important?


It’s not some teen text-speak they warn you about on the Nightly News, DWR stands for Durable Water Repellent, and it’s been a mainstay in the outdoor apparel industry for years. It’s what makes rain bead up and roll off your jacket, pants or—in our case—blanket. DWR works by creating a super thin surface on top of the nylon that microscopically increases the surface area of the blanket. When a drop of water lands on the coating, it holds the droplet above the fabric so it can’t seep in (think baby Simba in the Lion King. Rafiki is the DWR, Simba is the water. Flawless metaphor). By maintaining its droplet form, water can easily roll off the blanket.

It’s not just for rain, either. Not every Rumpl hits rainy PNW hiking trails every weekend; some barely make it off the couch (and only then to the fridge). DWR makes our blankets super spill resistant. We’re not saying you can play flip cup on one without getting it dirty, but we’re not not saying you can't play flip cup on one either.


Using a wash like Grangers can quickly refresh your blanket’s water repellency. To wash your Rumpl Original Puffy and Down Puffy Blankets, just follow these steps (from Granger’s site):

  1. Use two 50ml capfuls per garment. For best results, we recommend washing waterproof garments separately.
  2. Wash on a full cycle (wash, rinse, and spin) at 30°C or 86°F
  3. Heat activation is required for this product to work correctly. Tumble dry on low heat.  Don’t use an iron or hair dryer.

The process for reapplying DWR to our Sherpa Blankets is a little more involved. The plush sherpa fleece doesn’t love the DWR shield, so make sure you’re only treating the nylon or microsuede face. Apply it with a DWR spray bottle and then toss it in the dryer on low. Again, don’t use an iron; you aren’t pressing a suit, and this will melt the fabric.


Historically, outdoor companies have used what is referred to as a C8 DWR treatment. It’s incredibly durable and water-resistant, though it has a major downside; its byproducts are toxic and persist in the environment basically forever. For years our industry has been researching alternatives that create less waste while maintaining the same performance. Rumpl currently uses what’s called C4 in our DWR coating. Molecularly, it’s a “shorter” version of C8; its byproducts break down quicker, reducing the impact on the environment. That said, it’s not a perfect solution, and Rumpl has been heavily invested in transitioning to a more environmentally friendly solution as soon as possible.