I used 3 cans of outdoor waterproof fabric spray in black to cover 3 base cushions and 6 back cushions of an outdoor corner sofa. The cushions were originally cream and had been ruined by mould. I was very impressed with how well the spray covered and absorbed in to waterproof polyester. I will just need one more can to finish off some patches. I found that using a cloth to rub the spray in, particularly along seams, gave the best coverage. I wouldn’t hesitate to recommend this.