"If it can be written, or thought, it can be filmed..." STANLEY KUBRIC
Abrasion Marks
From Encyclopedia PRO
Scratches on the emulsion surface caused by scratching, improper handling, grit, emulsion pile-ups, and certain types of film damage (e.g., torn per- forations). Abrasion Marks can also happen due to traces of dirt trapped between layers of film as it is wound on the spool, dirt in the film holder or grit on the pressure plate.
A supercoat of gelatin, a few micrometres (one micrometre is 0.001 millimetre) thick, protects the film emulsion from scratches and abrasion marks.