^^^McMaster-Carr sells that pretty cheap, believe it or not (never but it from a stereo shop; the mark-up is incredible, much like "Hi Lift" jacks (cost = $15; 4x4 sell for $90)
Quoting GVR4_1057:
I have thought about mylar homewrap. Then I realized that I would have to buy $100.00 worth that could wrap a house. Any one know where to get smaller quantity?
I used the mylar from our plotter...stuff's pretty pricey, but they were going to throw out half a roll, so why not!