As well as a library-wind, putting a half-turn in the tape as it leaves the spool reduces edge-damage from a warped spool. Undoing the half-turn as it feeds the take-up spool makes everything tickety-boo again!

Has anyone else experienced temporarily-warped plastic spools caused by very thin tape compressing the hub? Unlikely to be a problem in a studio environement but here in academia........

From: Association for Recorded Sound Discussion List [[log in to unmask]] on behalf of Tom Fine 

Where did this phantom concern about warped plastic reels come from? As I said, who cares if they
are a little warped? Just library-wind the tape off them and replace them.

-- Tom Fine