Also spelled duvetine, duvetyn, duveteen. Pronounced "Doov-ah-teen," although Ive heard one Ph.D. of theatre say "Dove-ton." A lightweight flannel-like fabric. Although available in many colors, only black used in theatre, usually. Fairly inexpensive and available in rolls 54" wide. Some feel it possesses magical properties, in that anything covered with black duvetyne instantly becomes invisible to the audience.
http://www.filmtools.com/duv54rolx50y.html
http://www.filmtools.com/duv54rolx50y.html