The easy to use, safe, high performance wash-in waterproofing for softshell clothing. Adds Durable Water Repellency and revives breathability - in a washing machine. How Nikwax SoftShell Proof Wash-In protects. Nikwax SoftShell Proof Wash-In is easy and quick to apply in a washing machine, and its highly Durable Water Repellency (DWR) develops on air drying. The washing machine application ensures that the treatment goes right through the garment, treating seams, tapes and cords, as well as the fabric. Also, as the need for tumble drying is removed, this saves energy and protects more vulnerable, older, garments from heat. Nikwax SoftShell Proof Wash-In has been specifically designed and optimised for softshell garments; it leaves a flexible water repellent treatment on individual fibres allowing moisture vapour to pass through, maintaining breathability. Like all Nikwax products, Nikwax SoftShell Proof is safe to use. Nikwax takes great care to minimise the effect of Nikwax products on the environment and on you, the consumer. Nikwax waterproofing products are water-based, non-aerosol, non-flammable, non-hazardous and environmentally friendly. They contain no harmful solvents or volatile organic compounds (VOCs), and are completely free of fluorocarbons (which have been shown to be persistent in the environment and have been associated with serious health issues).