MaryKate Mildew Stain Remover is fast and effective. Its fine mist spray won’t run, even on vertical surfaces. No scrubbing necessary. Just spray on, wipe off. Use on any vinyl or hard surface. Applications: Marine canvas and fabrics, boat covers, bimini tops, seat covers; marine grade fabrics such as Sunbrella and other acrylic, synthetic, polyester, and vinyl marine fabrics.