What is Mylar?

What is Mylar?

 Polyethylene Terephthalate
Chemical structure of polyethylene terephthalate

Mylar, also known as BoPET (Biaxially-oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties, and electrical insulation.

BoPET film was developed in the mid-1950s, originally by DuPont, Imperial Chemical Industries (ICI) and Hoechst. The term, ‘Mylar’, is presently a registered trademark of the DuPont - Teijin Corporation.

Because polyester film is less permeable to gasses than other plastics, it is often favored in the food packaging industry. When used as a laminate, e.g., aluminum foil / polyester / LLDPE, it provides increased shelf life and freshness, as well as an excellent barrier against moisture and gas, notably oxygen.

Vacuum metallization, also known as thermal evaporation, is the most common PVD (Physical Vapor Deposition) process used to apply metal alloys under vacuum. Where polyester film is concerned, aluminum is vaporized inside a vacuum chamber, and then bonded to a polyester sheet to achieve a uniform metalized layer. This process produces the silver-colored material often incorrectly referred to as "myar" by consumers, while the appropriate term is "metallized polyester".

Shop Flat Mylar® Bags

Pouch Size: Less than 6"

Ideal for: Small products & devices; snack & sample portions; pharmaceutical applications

Pouch Size: 6" - 15"
Medium Bags

Ideal for: Long term food storage; product protection; apparel & shipping applications

Pouch Size: 15" +
Large Bags

Ideal for: Bulk processing & ingredient storage; box lining; large item oxygen and moisture removal

7.0+ mil thickness
Heavy Duty Bags

Ideal for: Items which require extremely low MVTR packaging; High barrier packaging starting at 7.0mil thick.

Zipper Pouches

Ideal for: Those looking for flat Mylar® bags with a zipper


Ideal for: Those looking for Mylar® barrier packaging with a spout

Stand Up Pouches

Ideal for: Those looking for gusseted bags that stand up on shelves

Drum Liners

Ideal for: Those looking for a round bottom gusset to use as pail liners.

Interested in Learning More?

Right Sealer for Your Setting

A hermetic seal on flexible packaging can be achieved with any of our sealing machines, this quick guide will help you choose the unit that will work best for your production needs.

Choosing a Vacuum Sealer

Not every Industrial Vacuum Sealer applies to every application. There are different models and types of Vacuum Sealers available, and each one of those sealers has different features that can affect the way a production line works.

Sealing Equipment Services

We design and manufacture custom sealing equipment to meet the unique needs of our customers. In addition to new machinery we even retrofit our customers’ existing equipment, regardless of the brand.