Hi, Grade A cotton, with three coats of nitrate clear, followed by several coats of aluminum for sun protection, following by 5 or 6 coats of Cub Yellow. Later versions used only nitrate dope for filling and butyrate dope for color coats. Restored Cubs use mostly Ceconite but still many use the nitrate and butyrate dope, some use two part Polyurethane. Dopes look better on cubs. Norm