The different types of Mylar bags based on material composition and functional design include PET, foil-laminated, metallized, kraft, side-gusseted, ziplock, vacuum-seal, child-resistant, and smell-proof variants. PET Mylar bags provide strength but rely on added layers, while foil-laminated bags deliver maximum barrier protection, and metalized bags offer moderate protection for shorter storage. Kraft Mylar bags focus on sealing, flexibility, and retail appearance, depending on internal materials for barrier performance. Side-gusseted, ziplock, and vacuum-seal bags improve capacity and oxygen control, while child-resistant and smell-proof bags improve odor containment.
The 9 different types of Mylar bags, such as PET, foil-laminated, metallized, Kraft, side-gusseted, ziplock, vacuum-seal, child-resistant, and smell-proof, are as follows:
Polyethylene Terephthalate (PET) Mylar Bags
Polyester (PET) mylar bags are made of stretched polyethylene terephthalate as the main layer, which gives the bag strength and structural stability. PET handles temperature changes reasonably well and resists tearing under normal use. On its own, PET film provides limited resistance to oxygen and moisture transfer, but lamination with foil or polyethylene layers increases barrier performance against air, humidity, and light.
Foil Laminated Mylar Bags
Foil-laminated mylar bags are made of an aluminum layer placed between plastic films, which significantly improves barrier performance. The foil blocks light entirely and reduces oxygen transfer to very low levels. The barrier structure of these foil-layered mylar bags directly supports long-term storage of products, as oxygen transmission rates drop to near-zero levels and light penetration is effectively blocked. The aluminum foil layer makes the bag stiffer than PET–PE laminates, but this added stiffness helps keep sensitive products stable.
Metalized Mylar Bags
Metalized mylar bags consist of a thin metal coating instead of a full foil layer, which makes the mylar bags easier to handle. The metalized coating on the outer side of metalized mylar bags offers a reasonable level of protection against light and gas exposure. However, the metalized barrier is not as strong as full foil, so they are better suited for moderate storage needs, such as snacks for 3 to 6 months.
Kraft Mylar Bags
Kraft mylar bags consist of an outer kraft paper layer combined with inner Mylar or foil laminates, offering a slightly more eco-friendly appearance. The exterior kraft material gives a more natural, retail-friendly look that many brands prefer. The barrier performance of Kraft mylar bags depends on the internal layers rather than the paper surface outside. The Kraft mylar bags are commonly used for dry foods and supplements.
Side Gusseted Mylar Bags
Side-gusseted Mylar bags expand along vertical folds, which increases storage capacity without widening the front panel. The BoPET-layered structure of side-gusseted Mylar bags supports the storage of heavier contents and allows better stacking during transport. They are commonly used for bulk products like coffee, grains, or feed. The shape of side-gusseted Mylar bags makes them efficient for volume packing and transport, but for upright retail display, they are considered less stable than other types of Mylar bags.
Ziplock Mylar Bags
Ziplock Mylar bags feature a press-to-close zipper that supports repeated opening and resealing during product use. The integrated lock closure suits products consumed in portions, such as snacks, supplements, and dry herbs. The zipper limits air and moisture entry after opening, but it does not create a complete oxygen barrier. In the United States, thin retail items are commonly packaged in ziplock Mylar bags because consumers prefer easy access without full disposal of the package.
Vacuum-Seal Mylar Bags
Vacuum-seal Mylar bags remove internal air before sealing, which reduces oxygen concentration and slows oxidation reactions. The multilayer lamination, often PET–foil–PE, resists collapse after air extraction and limits punctures under internal pressure changes. The vacuum-sealed features of Mylar bags support long-term storage of dry goods, such as grains, dehydrated vegetables, and powdered foods.
Child-Resistant Mylar Bags
Child-resistant mylar bags consist of locking closures that require a specific sequence of actions, such as push-and-slide or pinch-and-pull, to open, reducing the risk of accidental access. These child-proof bags are commonly used for packaging and storing pharmaceuticals, supplements, and herbal products. These child-proof bags often comply with certification and regulatory standards such as ASTM D3475 for child-resistant packaging performance and CPSIA labeling requirements in the United States.
Smell Proof Mylar Bags
Smell-proof mylar bags are made with multi-layer laminations such as PET–foil–PE, which reduce odor permeability by limiting oxygen transmission. The layered structure of smell-proof Mylar bags supports discreet storage of products with strong or volatile aromas, such as dried herbs, coffee, and nutraceutical powders. But odor containment of the smell mylar bags works only when the heat seals stay unbroken and the closures close fully along all edges.