Today I would like to help unravel the mystique of the Mylar bag. As with the ubiquitous oxygen absorber, the mention of Mylar bags brings up as many questions as there are answers. We have all heard that the best way to store dry goods for long term storage is in a Mylar bag but what exactly is a Mylar bag and, more specifically, how are they used?

What is a Mylar bag?

First and foremost, the term “Mylar” is actually one of many trade names for a polyester film called BoPet. For the technically inclined and the curious, that stands for “Biaxially-oriented polyethylene terephthalate”. This film was developed by DuPont in the 1950’s and was first used by NASA.