What is the best way to clean old wall paint from the edges of a shower stall? I believe the shower is fiberglass - is there an easy way to tell whether it is fiberglass or another material? The bathroom has seen many colors with the previous owners including bright pink, bright green and white, all of which are on the stall's outer edges - apparently no painter's tape was used, and they didn't cut in very well... It does not peel, and scraping etches the stall's finish. If I do remove it with a utility knife and it scratches the shower, is there any sort of shower stall makeover kit, where I could also sand/refinish the shower stall itself and give the whole shower a nice new finish when complete?