Mylar Bags: Uses and Limitations for Cannabis Storage

Mylar bags have garnered widespread acclaim for their variety of uses and protective features, making them go-to barrier bags for many industries. However, they’re far from the best option for storing cannabis.

What is a Mylar Bag?

Chemical company DuPont developed Mylar in the 1950s and trademarked the biaxially oriented polyethylene terephthalate (BoPET) film, often referred to as a polyester film. Mylar bags have layers of this polyester film with other materials to enhance their overall protective qualities. Renowned for their strength, chemical stability, and excellent barrier properties, Mylar bags are popular in many end-use industries including food and beverage, cosmetics, personal care, and electronics.

Benefits of Mylar Bags

High Tensile Strength and Durability

One of the standout features of these bags is their high tensile strength, reducing chances for tears and punctures. This strength is important for long-term storage applications where maintaining the integrity of the contents is crucial. 

Whether storing food, important documents, or sensitive equipment, Mylar bags provide a robust and reliable solution for long-term preservation.

Excellent Barrier Properties

Mylar bags provide a barrier against moisture, light, and gasses. They can keep moisture out, helping to extend the shelf life of many stored items. The addition of aluminum foil in some Mylar film and bags enhances these barrier properties, offering greater protection against environmental factors like UV radiation, oxygen infiltration, and temperature fluctuations.

Versatile Applications

• Food Storage: Food-grade Mylar is ideal for long-term food storage and food packaging, as it effectively preserves the freshness and nutritional value of dry goods like grains, beans, and dehydrated foods. They can also protect against moisture, light, and air as food storage bags to ensure items remain safe and edible over longer periods.
• Emergency Supplies: When it comes to emergencies, Mylar is invaluable. The material can be perfect for storing dry goods like emergency food, emergency blankets (space blankets), and medical supplies. The material’s durability and barrier properties help maintain the integrity of these critical items in times of need.
• Industrial Uses: Its high dielectric strength makes it an excellent electric insulator. The material is also great for solar filters, protective coatings, and as a substrate in flexible printed circuits.
• Medicine and Supplements: The pharma industry uses this material for packaging medications and supplements to reduce the potential for decay. 
• Document Preservation: Its resistance to moisture, oils, and acids makes it an option for preserving important documents and archival materials. Libraries and museums turn to Mylar to protect historical records and valuable papers from breaking down.
• Industrial Applications: It works well in the production of solar panels, insulation materials, and electronic components.
• Gardening and Agriculture: In hydroponic and traditional gardening, Mylar sheets are used to enhance light reflection, promoting plant growth. They help create an optimal growing environment by maximizing the efficiency of available light.

Why Mylar is Not Ideal for Cannabis Storage

It doesn’t breathe

Cannabis storage requires a delicate balance of humidity and airflow to maintain the plant’s potency, flavor, and overall quality over time. While Mylar bags are popular for their excellent barrier properties, they lack the breathable nature required to regulate the bag’s headspace. This limitation can lead to several issues in your crop, including a stale environment, trichome degradation, and a lack of proper humidity control.

It doesn’t protect terpenes

Another significant drawback of using Mylar bags for cannabis storage is their lack of terpene preservation. Terpenes are highly volatile compounds, meaning they can easily evaporate or degrade when exposed to harsh conditions. Mylar’s limited airflow and potential for trapped moisture can lead to severe degradation, resulting in a loss of the unique aroma and flavor of the cannabis.

Mylar bag alternative: Grove Bags

When it comes to preserving the freshness, potency, and flavor profile of cannabis, Grove Bags stands out as a specialized solution tailored to the unique needs of cannabis storage. With advanced TerpLoc® technology, we offer a sophisticated balance of chemical stability (humidity control and gas exchange capabilities) while effectively shielding the contents from detrimental factors like UV light, static charge, and oxygen exposure.

Detailed Comparison: Mylar Bags vs. Grove Bags

See a detailed comparison of TerpLoc vs Mylar for more information about these two materials.

FAQ

Are mylar and aluminum foil the same?

No—although they are both materials used for packaging and insulation purposes. 

Mylar is a polyester resin stretched into thin sheets, providing strength, flexibility, puncture resistance and excellent barrier properties against moisture, gasses, and light. Aluminum foil is made from aluminum, which is melted, pressed into thin sheets, and rolled. It’s great for its flexibility and barrier properties against light, moisture, and bacteria.

What shouldn’t you store in mylar bags?

PET bags are not ideal for storing foods with high moisture content. That moisture can create an environment conducive to mold, bacteria growth, and spoilage, which can compromise food safety and lead to spoilage even with oxygen absorbers. They’re also not ideal for storing liquids, foods with strong odors, perishable items, chemicals or hazardous materials, or items that require very specific storage conditions.

Can you vacuum seal mylar bags?

Yes, you can vacuum seal Mylar bags under certain conditions and with the right equipment. Vacuum sealers can enhance the storage capabilities of the bags by removing excess air and creating a more compact and airtight seal when the film is heat set.

How do you seal mylar bags?

Fill your bag with the desired contents, making sure to leave just enough room at the top for sealing. Place the open end of the bag between the jaws of the sealer, and press down on the sealer’s arm—or activate the sealing mechanism, depending on the type of sealer. Hold the sealer closed for as long as instructed.

After sealing, allow the bag to cool for a few seconds before handling; this ensures that the seal sets properly and prevents accidental opening. Once the bag cools, you can inspect the seal visually and by touch. A properly sealed bag will have a tight, flat seal without any gaps or wrinkles along the sealed edge.