i have tried and tried and tried to find real mylar. the best i could find was metalic sheeting and it was pretty expensive. so i settled with panda film it works well and its cheap as hell about a buck a foot. you can save yourself some stress and go to yellowpages.com and look for a good hydroponics store instead of going to home depot, lowes, ace ect. i live in a small town and drove 2 hours out of my way to go to the nearest hydroponics store because as a rookie grower i needed more help and info than what all those chain hardware stores could provide. so hope this helps. my main point is find a good hydroponics store like garden tech or the grow shop the people that work there usually grow weed so they will know how to help you just tell them your looking to grow "tomatos" lol. and listen to all the veteran growers on this site, they will pretty much hold your hand through everything. anyway good luck with your grow.