Sprinkle a little water on a clean, dry spot. If it beads and rolls off, the finish is working. If it darkens the fabric and soaks in, it is time to re-treat. Clean the canvas and let it dry completely first, work outdoors on a calm day, cover nearby vinyl, clear windows and gelcoat, and apply the treatment following the directions on the container. Let it dry fully before you fold or roll it. Treatments are for woven canvas and woven cushion fabric only, never marine vinyl or clear vinyl.