Once a fabric is soaked, insulation and breathability are compromised. KUIU’s Durable Water Repellent (K-DWR) treatments resist water, keeping it from penetrating the outer layer. This increased breathability and performance allow waterproof membranes to evaporate your sweat while blocking out moisture. K-DWR, also enhances dry-time and protects from light rain or dew-soaked vegetation on non-waterproof products.