ESL diaphragm film

Hi whoever's reading this.

I've been planning to build a pair of ESLs for a while now, and I've figured out where I'm buying everything from, except for the mylar film.
I've been looking for mylar film which is about 5 microns thick for a few months now, and the closest thing I can find is 12 micron mylar or 6 micron composite film for RC planes.
Does anyone know of an online vendor who sells 5-6 micron mylar film?

Sorry that it's such a boring question.

Thanks in advance,
Jo