How much weight will the fabric gain on using Nikwax products?
Although there is water in Nikwax products, this evaporates to leave the water-repellency behind. An application of UV Proof, for example, results in a gain of 1 to 4% dependant upon type of fabric, condition of the fabric & how water-repellent it was already. As an example – Pertex gains less than 2% in weight.