What is DWR Coating? Here’s What You Need to Know

A tech backpack is exposed to the elements, whether you are exploring the world, climbing Mt. Everest, or commuting on a rainy day. So, to protect your tech, you need a backpack with a durable water-repellent coating (DWR coating). Wait, what? I know it sounds technical (that was my reaction, too, by the way). And so today, let’s talk about this type of water-repellent coating for backpacks: what is DWR coating, how it works and why it matters. 

DWR Coating, Explained

DWR is a treatment that resists water. It is typically applied to outdoor outerwear accessories (and backpacks) to improve performance in wet conditions and weather. It causes water to bead up and slide effortlessly off the fabric’s surface, preventing moisture, rain, or snow from saturating its exterior. This coating helps non-waterproof items withstand mild weather or mist and protects gear whether you’re brushing through wet foliage or caught in a drizzle. 

How Does It Work?

DWR is a practical and straightforward mechanism that keeps the contents of your backpack dry and safe from a sudden downpour. It makes the fibers on the outside of the fabric water-repellent by creating a “spiky” surface like the bristles of a brush. 

This increases the surface tension when water comes in contact with the surface, causing the water molecules (again) to band together on the fabric’s outer edge. However, the DWR coating loses its water-repelling properties over time, causing the water to spread across the fabric’s surface and soak through. 

How to Care for DWR Coating

As mentioned, it will lose effectiveness over time due to many factors that clog and flatten the fibers. Some include oil, dirt, sunscreen, and other items that may hamper the coating’s ability to resist water.  

• Maintain it with products designed for technical fabrics, like Nikwax Tex Wash. These products do not contain additives that will stick to the fabric’s surface and affect its performance. 
• Keep your EDC backpack clean,  avoid exposure to high heat, and do not use harsh detergents. All these can break down the coating. 
• Depending on usage, you should reapply after every wash or every few months.

How to Reapply DWR

Reapplying the treatment is simple and will not take much of your time. Here’s the process to restore your backpack’s water-resistant properties. 

Clean the bag

• Remove all items and brush off dirt from your bag.
• Check the care label and see if the manufacturer allows washing your bag with a mild detergent. Do not use fabric softeners, as they can reduce DWR’s effectiveness.
• Handwash with cold water, then rinse well, ensuring no residue is left behind.
• Dry your bag entirely. 

Select the right product (*suitable for your backpack’s fabric)

Wash-in forms and spray-on options are available. Here’s a brief overview. 

• Spray-ons are ideal for targeted areas, such as shoulder straps, zippers, and other high-wear areas. 
• Wash-ins work better if you need to treat the entire backpack. You’ll need a washing machine for it. 

DWR Coating Application

Check out the following for a general guide. (*Read and follow the manufacturer’s instructions.)

For the Spray-On DWR

• Hang your bag outdoors or in a well-ventilated area. 
• Shake the bottle before use to mix all the ingredients thoroughly. 
• Spray the product evenly! Hold it six inches from the bag’s fabric, then spray it over the entire surface. Focus on the areas with the most wear. 
•  Wipe off any pooling or excess dripping. 
• Allow product absorption based on the manufacturer’s recommendation. 

Depending on the coating you’ve selected, heat activation may be needed. To apply heat, set a hairdryer on a low setting, or you may tumble dry your pack on low heat. 

*Read the bag’s care label before applying heat, or it might damage the fabric

For Wash-In DWR Application

Use cold water and a gentle cycle on your washing machine. Pour the recommended DWR wah-in product amount into the detergent compartment. Put your bag in the washing machine and start running it. Dry your pack entirely after washing. Use low-heat tumble-dry if heat activation is recommended. 

Testing Water Resistance

To do this, sprinkle water on the bag’s surface. Check if the water bands together and rolls off the fabric’s surface. The coating has been applied successfully if it does. But if you notice it soaks in, reapply the DWR and ensure it’s done correctly, following the above steps. 

DWR in Tech EDC Backpacks: The Benefits

Its primary benefit is protecting your bag contents from snow, rain, and moisture, especially if you always carry electronic devices, such as tablets, laptops, and phones, which are susceptible to water damage.

Unlike fully waterproof bags, DWR maintains breathability in the fabric, ventilating the inside and preventing condensation. DWR keeps food and clothes dry if backpacks are designed for outdoor activities. 

This coating also extends the life of your backpack because it protects the fabric from factors that weaken it, such as water, grime, and dirt. This ensures your backpack can withstand harsh conditions and frequent use. 

DWR-treated fabrics are lightweight and flexible, unlike waterproof materials, and are perfect for extended wear during long hikes or daily commutes. So, while they offer maximum protection, they add only minimal weight.  

Final Thoughts: DWR Coating Matters for Your Backpack

Whether you’re a commuter, traveler, or outdoor enthusiast, understanding DWR, how it works, and IP ratings (how waterproof your backpack is) can help you make an informed decision when selecting an EDC backpack.

If you live in a wet climate or spend much time outdoors, you’ll need a backpack with DWR coating. This provides a protective layer for your tech, ensuring it stays dry when caught in a drizzle or navigating wet foliage.