nitrocellulose lacquer
A resin created by treating cotton or other cellulose products with nitric acid to produce solvent-soluble clear coating materials. It was found in the 1920s that this could produce a very durable, color-carrying lacquer. Used first as a paint to produce more than just black automobiles, it further found its way to other construction uses due to being the first easily sprayable quick-drying resin. (Preservation Science, 2019)