What are the sources of scratches on film?

[dnk512]

Melanie, I have seen odd looking scratches like the lines in your image on film that was left on a hard surface and then a book or folder was thrown on it :-(

 

[RJBender]

Keep in mind that (for scans at least) scratches & dust on slides are harder to see. On negatives they will show up white, on positives they will show up black.

Are you referring to slides only, or b/w film negatives? On the first roll I developed at home, some of the negs I scanned had what I thought were scratches on them, or dust. I figured I was careless somehow. Can anyone interpret the white marks on this? At first I thought "dog hair," but the marks are way too small. Dust?

Was it cold outside when you took that photo and did you rewind or advance your film quickly? If so, the marks could be from static electricity.

R.J.