Wipe off as much as possible with a clean dry cloth and spray a FINE mist of Lysol on to the jacket from a distance, so as not to soak the jacket. Then let it air dry. The problem with mold and mildew is it keeps growing back if you don't kill it. I have never ruined an album cover with Lysol.Just go easy with it. If you soak it, the paper cover will lift off the cardboard. The fine mist of Lysol will kill the mildew and air drying allows a light residue of Lysol to remain on the jacket to inhibit further growth problems. Keep any mildewed albums separated from other albums so as not to "infect" any other jackets with the problem. It is a living thing and will move onto your other albums.
