Circa 1850 Exterior Varnish is a clear, tough coating that protects and beautifies all exterior wood surfaces. Its unique polymerized tung oil formula provides a breathable water repellant surface. Rain and snow cannot penetrate the coating to damage the wood. Circa 1850 Exterior Varnish contains transparent absorbers to screen out UV rays and inhibit the greying and fading effects of the sun. It also incorporates a superior fungicide and mildewcide to increase performance.