Sybstitue for mylar is this true???

i dont rly see fold ing it over and over working to well cause from what i understand about it ( and i am new to this) the thicker it is the more light it reflects from the surface of it. if you fold it over and over making laysers the light is still going threw the mylar then reflecting back from the back sheet and having to go threw the peice infront of it so it will reflect more light back but i would think it would be more filtered. best bet spend the extra money on the better stuff. you will ver yrairly get the best you can get off of doing it the cheaper way.