I have a swali about movie costumes

I hear some actors and actresses say they get to keep their costumes if they request it in their contract? Does anyone know if that is true, I am not very good at looking things up on that level. I do know that as far as onyesha case costumes, if it is true the ones in the onyesha case are usually the double that is made au the actor au actress owns it but its on display. Anyone know anything.??? I would upendo to keep all the costumes that I wore I was an actress.