My procedure: Soap, water, and careful DABBING (not rubbing) with a soft cloth. Old paint on Masonite can tend to flake, and rubbing during the cleaning process can remove flakes of paint. It's possible that a painted Masonite sign like this may not come bright, squeaky clean. So, don't overdue your cleaning attempt. John
Last edited by Jolly-John; Mon May 21 2018 09:56 AM.