DWR vs PU: What’s the Difference and Why Does It Matter?

Dive into the material technologies that keep your gear dry!

When shopping for outdoor gear, you might have heard of Durable Water Repellent (DWR) and Polyurethane (PU) or perhaps these terms are new to you. Either way, if you’re curious about how these two technologies differ and how they work to keep you and your gear dry, you’re in the right place. Let’s break it down so you can understand what makes each one unique and why they're important. 

What is DWR?

DWR is a chemical treatment applied to the outer surface of gear to make it water resistant. It works by reducing the surface tension of fabrics, causing water to bead up and roll off rather than soaking in. Unlike coatings that cover the entire fabric surface, DWR works by coating individual fibers, leaving microscopic gaps. This clever design keeps the fabric dry while maintaining breathability, ensuring you avoid the damp, clammy sensation often associated with wet gear. Thanks to its effectiveness, DWR is a go to treatment for rain gear and other outer layers, providing reliable protection without sacrificing comfort. However, DWR isn’t fully waterproof. Over time and with prolonged exposure, water can eventually soak through.

What about PU?

Take a look around the space you’re in, likely there are multiple items that contain PU such as flooring or shoes. When it comes to the textile industry, PU plays a key role. In its liquid form, PU is applied as a coating or laminate to one side of fabrics like polyester, nylon, or cotton, transforming them into completely waterproof materials. Unlike DWR, which repels water on the surface, PU creates a fully impenetrable barrier that prevents water from passing through the fabric entirely. This makes it the preferred choice for gear requiring absolute waterproofing, such bags and tents.

PU coatings enhance the abrasion resistance and elasticity of fabrics, making them remarkably durable and able to withstand the wear and tear of your most rugged adventures. On top of their performance, they’re incredibly versatile. PU coatings can be customized to achieve the look and feel you love in your favorite brands, from glossy and bold to muted and understated, or even transparent finishes. Many of the products you rely on every day wouldn’t be possible without PU coatings.

We all love PU and DWR for keeping us warm and dry—but what’s the catch?

PU coatings have often been considered the “lesser evil” compared to DWR. Traditional DWR finishes rely heavily on polyfluoroalkyl substances (PFAS), often called “forever chemicals.” These substances don’t break down easily in the environment, persisting for centuries and accumulating in living organisms. PFAS excel at repelling water, dirt and oils, but come with a heavy cost. They have been linked to hormone disruption, reproductive issues, immune system damage, and other serious health risks. As they slowly degrade (over as long as 1,000 years), they leach into waterways and the air, harming ecosystems and human health alike.

So, PU seems like the better option, right? 

Not so fast.

Traditional PU coatings also come with their own baggage. They often rely on CMR (carcinogenic, mutagenic, and reprotoxic) solvents that evaporate into Volatile Organic Compounds (VOCs), which are major contributors to air pollution and pose serious health risks to those working with the coatings. On top of that, solvent-based coatings frequently use “forever chemicals” similar to those used in DWR finishes, compounding the problem.

You might be wondering: Why haven’t we switched to something better? 

That’s where PolyCore comes in.

We’ve developed a water-based PU coating that eliminates both CMR solvents and PFAS chemicals entirely. In the past, the outdoor industry lost faith in water-based technologies due to poor performance, but PolyCore’s patented coating process and formulations have changed the game. These solutions don’t just compete with solvent-based PU coatings, they outperform them.

Is it possible for DWR and PU to work together?

Yes! To keep your items dry, the best gear combines both technologies, leveraging their strengths for optimal performance. Fabrics coated by PolyCore utilize a water-based PU coating on the back of the fabric and a C0 DWR on the face. The PU coating does the heavy lifting, providing extremely high abrasion resistance, up to 10,000 mm hydrostatic resistance, and doubles tear strength of the base fabric. Meanwhile, the C0 DWR provides extra water resistance and prevents the fabric from wetting out. Together, these technologies create gear that’s waterproof, durable, and eco-friendly.

So, ask yourself: Are you willing to pay a little more for products that protect both you and the planet? If your answer is yes, it’s time to make your voice heard. Demand that the brands you know and trust make the shift to water-based PU coatings. Together, we can push the industry toward a healthier, more sustainable future.