What Are Mylar Bags Made Of?

These are packaging bags made from Mylar film, which we depend on for food preservation. Mylar bags are especially great for storing perishable goods.


They are available in a range of sizes, and we can even cut and create them in custom shapes (A.K.A. “diecut”), which allows you to order them based on the size, shape, and amount of products you intend to keep and sell.

What Are Mylar Bags Made Of?

Custom mylar bags don’t only look stylish and professional—they also keep their contents’ smell concealed and increase the longevity of your product’s shelf life.


You have probably used these bags at home to store food and grain and may have wondered what they are made of. So, what are mylar bags made of?


In this post, we answer most of your questions regarding these hardy, flexible packaging bags.


What Are Mylar Bags Made Of? So, What is Mylar Anyway?

“Mylar” is a trademark owned by the firm DuPont.


At the start, this company produced and sold BOPET (biaxially-oriented polyethylene terephthalate) films. BOPET is a polyester film derived from P.E.T. (polyethylene terephthalate).


Mylar is made with polyester, specifically polyethylene terephthalate (P.E.T.). Since it comes in a film format for our packaging purposes, P.E.T. is stretched evenly and produced as rolls of a thin film.

What Are Mylar Bags Made Of?

P.E.T. is known for its smell and gas barrier properties, reflectivity, transparency, electrical insulation, high tensile strength, dimensional and chemical resilience.


Because of these properties, mylar packaging bags are flexible, light, and thin, yet they are strong and durable.


What’s the Difference Between BOPET and Mylar Bags?

BOPET bags are becoming increasingly popular in the market, and the trademark “Mylar” is becoming more well-known.


As a result, most people now refer to the bags as “mylar bags” rather than “BOPET bags.” You can certainly use these terms interchangeably when referring to these silver film bags.


Why Does Mylar Look Metallic?

Mylar looks “foil-like” and is actually a film of plastic dressed in a metal coating.


As mentioned earlier, Mylar is made of plastic, and Mylar is actually not colored in its native form.


A chilled surface, such as a roller, receives an extruded thin film of molten P.E.T. plastic (polyethylene terephthalate). That process makes the Mylar film.


After this, a (condensation) chemical reaction known as vapor deposition deposits aluminum onto the Mylar’s surface to coat it evenly and permanently.

What Are Mylar Bags Made Of?

These look metallic because it is Aluminized Mylar, which is categorized as a “hybrid” material. It typically appears as foil but feels like plastic to the touch.


Our bags come with a layer of metalized BOPET, or BOPET coated with a thin layer of metal, usually aluminum foil.


Interesting Facts About Mylar Bags


FACT #1 – Mylar Bags Do Not Need to Be Refrigerated

When storing food in these packaging bags, you do not need to refrigerate the food after packaging.


However, since rodents can gnaw slowly through Mylar, you can store the packaged foods in a rodent-proof container to make sure it is 100% safe.


FACT #2 – You Should Use Mylar Bags in Conjunction with Oxygen Absorbers

As the name implies, we use oxygen absorbers to absorb any oxygen that may remain in the bag after sealing it. This also goes for any oxygen that may remain in the food.


Oxygen absorbers will serve to extend the food’s shelf life. It’s critical to know how much of it to use, though. Adding too little may cause your food to spoil more quickly, while adding too much is a waste of resources.


FACT #3 – Mylar Bags Have Been Used to Store Foods for Over Six Decades

The popularity of these bags has increased in recent years, yet the bags have been available for more than 60 years. Mylar was created in the 1950s by a firm called DuPont Chemical.


FACT #4 – Mylar Preserve Foods for Longer

When compared to other forms of food storage bags, Mylar bags can keep food items fresh for a considerably longer time.


This fact is especially true when you use a good vacuum sealer. Because of its metalized nature, it helps to keep oxygen, humidity, and light away from the food better than other food packaging alternatives.



-What Are Mylar Bags Made Of? FAQs-


  • Is Mylar the same as polyester?

Mylar is made of polyester. The accurate, generic term for Mylar material is polyester film.

“Mylar,” much like “Xerox,” is now a name commonly used to refer to plastic film material in general.

However, Mylar® is actually a registered trademark brand owned by Dupont Teijin Films. Dupont uses the term “Mylar” to refer to an umbrella of products they create from Polyethylene Terephthalate (P.E.T.).


  • What metal is Mylar?

Mylar is not a metal. Mylar is a registered brand name for P.E.T. or polyester terephthalate resin, a thin and transparent plastic.

Some Mylar films look metallic because an extremely thin layer of Aluminum is fused to it to provide preservative and protective barrier properties.


  • Does Mylar corrode?

Mylar will not corrode and does not stain because this film material is resistant to chemicals.


  • Why is Mylar shiny?

Mylar is actually a clear material since it is made of transparent polyester (P.E.T.). Mylar appears shiny when an extremely thin layer of Aluminum metal—thinner than 1/100th of the width of a human hair—is welded onto it.

This addition of Aluminum foil makes the Mylar highly reflective, with one side of the Mylar shiny and one side dull.


  • What foods can be stored in Mylar bags?

Examples of foods you can store in mylar bags are sugar, flour, pasta, beans, wheat, and other dry goods.

Only foods with oil and moisture levels of 10% or less can be stored in mylar bags. If you plan to store fruits and vegetables using mylar bags, ensure that they are dehydrated and completely dry.


  • Can I store rice in a Mylar bag?

It depends on the type of rice. You can certainly store white rice in a mylar bag.

Brown rice, on the other hand, has higher oil content and therefore is not well suited for long-term storage in a Mylar bag.


  • Are Mylar bags B.P.A. free?

All Mylar bags sold by Inkable Label Co. are 100% free of BPA and are safe for food packaging.

All of our material comes from reliable, long-standing suppliers who can vouch for the safety of their products.


  • What are Mylar bags good for?

Mylar bags, when sealed correctly, adequately protect foods from contamination, insects, light, degradation, and moisture. They create an effective oxygen barrier to extend the shelf life of its contents.

When appropriately sealed, Mylar bags also prevent smells from coming in and getting out and preserve their contents’ quality and consistency (dryness, crispness, freshness).