Thanks. We used mylar at the ad agency as overlays back in the 80s.
Is that the same stuff?
Not the same stuff, mylar storage bags have multiple layers and need to be food grade. Generally 4-5 mm thick. The mylar provides the oxygen barrier and there is another layer of plastic inside.
Lots of places to but them. pleasanthill grain carries a couple sizes that meet my needs and they are good quality. Read up on how to do it before you pack the food. Its not hard but you need to do it the right way.