DWR, or Durable Water Repellent, is a surface treatment that gives textiles hydrophobic (water-repellent) properties. In practice, this means that water droplets bead up on the surface and roll off instead of penetrating the fabric.
This treatment is widely used in outdoor and technical clothing, tents, sleeping bags, and backpacks. The purpose of DWR treatment is to enhance moisture resistance, reduce absorbency, and extend the performance and lifespan of the material. In addition to water repellency, it also makes fabrics easier to maintain and more resistant to dirt.
DWR treatment is often combined with membrane materials such as Gore-Tex. While the membrane ensures waterproofness and breathability, DWR prevents the outer fabric from becoming saturated. This keeps the garment breathable by allowing internal moisture to escape while shielding the outer layer from rain and snow.
Although DWR treatment is durable, its effectiveness diminishes over time. Natural wear and improper care — especially washing with harsh detergents — can weaken it. To maintain peak performance, it is recommended to regularly restore water repellency using specialized impregnation sprays designed for DWR finishes.