To most effectively benefit from the ultraviolet (UV) and Durable Water Repellent (DWR) protection of Nikwax Tent & Gear SolarProof it is best applied to equipment from new.During use the equipment fabric will pick up dirt and other contaminants which stop water from beading on the fabric surface. When this occurs the DWR can be revitalized by cleaning with Nikwax Tech Wash. Over time the DWR will wear off through use. Both the DWR and UV protection can be replenished by reapplication of Nikwax Tent & Gear SolarProof.