Nikwax Cotton Proof has been specifically designed and optimised for breathable cotton, polycotton and canvas materials; it leaves a flexible water repellent treatment on individual fibres allowing moisture vapour to pass through, maintaining breathability, prolonging the life of gear and optimising performance in wet weather. Nikwax Cotton Proof is easy and quick to apply in a washing machine and ensures that the treatment goes right through the garment. The highly Durable Water Repellency (DWR) of Nikwax Cotton Proof develops on air drying. Therefore the need for tumble drying is removed, saving energy.