These are marks which may result if the center of a roll of film is rigidly held while the outside end is moved. (Film Editing)
Found on
http://www.filmland.com/glossary/Dictionary.html#A
Not to be confused with sync marks. Cinch marks are small vertical scratches on a roll of film that are caused when the end of the film is pulled to tighten the roll, causing any dust on the film to make a small scratch. Too much drag on the supply while rewinding is one common way that cinching can occur
Found on
https://www.encyclo.co.uk/local/21112
No exact match found.
