"PVC" release films, achieving mirror like finishe

Hello

I have been reading on other forums that you can use a “PVC” release film to achieve mirror like finishes (gloss finish) on Vacuum bagged laminates straight from the vacumm bag.

I am having all sorts of problems locating the correct products, some suggest Mylar, but this is way to expensive and differcult to get the lengths I need.

Is there a cheaper alternative and does anyone have any suggested suppliers.

Cheers
Delbert.