Minute scratches on film surface caused by slippage between turns of a loose roll. 1
These short scratches on the surface of a motion picture film generally run parallel to its length. They are caused by dust or other abrasive particles between film coils, or improper winding of the roll, permitting one coil of film to slide against another.
Longitudinal cinch marks result when the centre of a roll of film is rigidly held and the outside end is pulled tight. Short scratches caused by improper winding are parallel to the length of the film, where one loop is forced to slide against the next one on a reel.
1 Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston