The width of the film stock or videotape. For photographic materials, the width of the original roll film from which the individual negative or print was cut.
Photographic. 35 mm; roll film 616; roll film 620; roll film 220; roll film 135 [source: rulib]
Film. Standard 8mm; Super 8mm; 9.5mm; 16mm; Super 16mm; 28mm; 35mm; Super 35 (Superscope 235); 35mm 8-perf (VistaVision); 55mm; 65mm; Imax (15/70 and 8/70); 70mm; Other [source: MIC Archive Directory]
Videotape. 1/4-inch; 1/2-inch; 3/4-inch; 1-inch; 2-inch; 6.35mm; 8mm [source: Wheeler]
Audiotape. 1/8-inch; 1/4-inch; 1/2-inch; 1-inch; 2-inch [source: rulib]