best reflective material?

hahaha, i went to go to this hydro store i found, and they closed down!!! hahaha, and i went to get a shockblanket, and they had mad thin ones for 10buks, but they were out, fuk. hahaha

10 dollars is alot for a single emergency blanket, If its REALLY that hard for you to mail order mylar just use FLAT white paint. That is not gloss, not semi gloss, but flat white as FDD said.....no matter what any paint expert says lol

yea but its easier for me to use the space blanket cos im gonna make my box outa cardboard :[]
haha, im gonna go up to 2 more outdoors shops lookin for space blankets today.

Flat white paint is good. Mirrors will burn your plants and so will most aluminum, unless you use the less-reflective side. You could try amazon and get Panda Film.