We take our canvas down each year. We scrub it well, with a little bleach and the 303 fabric cleaner. After it drys, we spray it with 303 Marine protectorant and fabric guard. We have 13 years on a slant back which stays out in the Florida Sun and humid weather. About the same on a Bimini cover. We buy the 303 products in gallon containers and either hand spray or a garden spray container. Bob Austin