best wall reflector?

What is the best wall reflector? for a 6.5ft by 6.5ft grow room?

I'm using 2mil reflective mylar for a 6x8

Flat white paint is a close second.

ok thanks people.

i heard dimond is the best? since it dosent make any ''hotspots'' of light

Bright white paint is usually the best to use. I compare it to getting blinded if I look outside on a sunny day when everything is covered in snow. It's bright as all hell lol.

I used to be all for the mylar, but a lot of mylar is too much like a mirror, and it can reflect hot spots. The diamond mylar that fshady mentioned is IMO the next best thing to bright white paint; it'll reflect light more evenly.

Sometimes growers build their setup with wood and are in too much of a hurry to paint that wood and seal it; even just missing small areas of bare wood might lead to problems. Wood exposed to humid environment tends to warp, grow more mildew, and overall isn't kosher. Plus you can wipe clean a nice white painted surface.