The back of this vintage wood and metal washboard explains that its washing surface is "made from a sheet of steel into which has been fused a coating of porcelain enamel (a combination of fine glass.)" The dark blue ribbed washing surface appears below a metal panel reading "National Washboard Co. Chicago Saginaw Memphis SOAP SAVER Trademark Reg U.S. Pat. Off. Made in U.S.A. No. 199 Patent 1152766-1283148." Great decorator piece for your country or primitive decor!