It’s used for wrapping up a film

SPOOL

Think of what holds the thread in a sewing kit or the reel that keeps old movie footage tightly wound.

The clue plays on the double meaning of "wrapping up." In filmmaking, "wrapping up" means finishing production, but here it hints at the physical object used to hold film—literally wrapping it around something. A spool is what film is wound onto, so the word "spool" fits both the literal and figurative sense of the phrase. The pun makes it a clever misdirection for solvers.