In response to the challenges of preserving the surfaces of its painted outdoor sculptures, the Object Conservation Department at the National Gallery of Art has undertaken research to compare commercial paint systems for physical and chemical durability. Specifically, black matte finishes are being studied, as they have been shown to be the most fragile and difficult to maintain among the sculptures in the collection. This paper evaluates the current condition of five matte painted outdoor sculptures at the National Gallery of Art, explores considerations for repainting, and describes ongoing comparative testing of nine commercial paint systems. This study seeks to help conservators provide informed recommendations to artists when choosing durable materials compatible with their aesthetic preferences. -- SCMRE