When used in reference to damage in a spa, bathtub, or shower, it means that the damage is limited to the surface. Most of these products are produced using some type of polymeric surface to provide the attractive aesthetics, which is reinforced with a stronger “backing” such as fiberglass reinforced polyester or strong polyurethane. Sometimes the surface has two layers. The second layer is normally another plastic such as acrylonitrile-butadiene-styrene (ABS).

A cosmetic repair is to re-establish the aesthetics of the surface so that the damage is undetectable, visually. Cosmetic damage can include blisters, cracks, crazing, burns, chips, and color change due to chemical attack.