Acrylic, polyurethane, epoxy and polyester exterior paints are suitable for fiberglass doors. Proper preparation and priming are also necessary. Oil-based and melamine paints and lacquers are ineffective on fiberglass surfaces, according to DoItYourself.com and SFGate.com.
The composition of a fiberglass door determines the ideal type of primer and paint to use on it. For example, epoxy primers and paints are ideal for epoxy resin fiberglass doors, and polyester primers and paints work best on polyester resin doors. Latex and urethane primers also work on most fiberglass doors, according to DoItYourself.com. Etching primers, however, are not suitable for use on fiberglass.