Remove the glass and back of frame. Sand the frame lightly and clean with a damp cloth. Cover the area where you are painting with newspaper and ensure it is well ventilated.
Always follow the instructions on the back of the can. For a better finish, apply a light coat of Rust-Oleum Surface Primer and leave to dry before applying the top coat.
Apply the spray paint in multiple light coats of spray paint to avoid any paint runs. Two or three light coats will be enough.
Leave the frames to dry for 24 hours, replace the glass, insert your photograph and re-fit the back of the frame.