Building new type of reflector & I have a question

Hi everyone,

I'm going to be starting a grow soon and I have an open area to use. Instead of putting up walls for reflection I'm going to build reflectors that sits low & don't block air flow.

I'm trying to decide what reflective surface to use. Logic tells me that mirros would make the best reflectors of all, am I right?

no ive heard and read mirrors are horrible
cheap way poly wrap reflective gift wrap sorta
and reflective tap at home depot