What was the covering on the outside of the Hindenburg?

The Hindenburg was covered with a fabric made of cotton and linen, which was coated with a mixture of aluminum powder and varnish. This coating was designed to reflect sunlight and reduce the temperature of the gas cells, helping to maintain the airship's buoyancy. However, it was also flammable, contributing to the disaster when the Hindenburg caught fire while landing in 1937. The use of this material has been a subject of analysis in understanding the catastrophic failure of the airship.