High-Barrier Structures
Metallized PET and foil-laminate constructions reviewed against oxygen, moisture, light, and aroma exposure and the target shelf life.
Mylar bag packaging
Source custom printed mylar bags as engineered high-barrier packaging—not a generic commodity—by coordinating the product, barrier and shelf-life target, bag format, closure, print, and order plan.

Direct answer
Custom Mylar bags are printed high-barrier flexible pouches commonly specified with PET film plus a metallized or aluminum-foil barrier layer and a heat-seal layer. A complete project coordinates the product, bag format, oxygen and moisture barrier, closure, printing, filling and sealing, food-contact documentation, testing, quantity, and delivery; the word Mylar alone does not define the finished structure.
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No finished specification required. Send a product or reference photo on WhatsApp.
Metallized PET and foil-laminate constructions reviewed against oxygen, moisture, light, and aroma exposure and the target shelf life.
Three-side-seal, stand-up, and gusseted formats with zippers, tear notches, hang holes, and heat-seal closures reviewed as a complete bag.
Explore bag features →Digital printing for lower quantities and multiple SKUs; flexographic or gravure routes for larger repeat orders.
Compare print routes →Long-shelf-life foods, coffee, snacks, powders, and supplements coordinated with barrier, sealing, and documentation needs.
See food packaging →Three-side-seal bags suit flat, dense, or vacuum-adjacent applications and efficient case packing. Stand-up formats add shelf stance and reclosure. Gusseted formats carry larger volumes. Zipper position, tear notches, hang holes, and gas flushing compatibility are specified with the format.
Mylar® is a trademarked name for biaxially oriented PET (polyester) film, while packaging buyers often use “mylar bag” when searching for metallized or foil high-barrier pouches. In practice, the package is normally a laminate: PET for strength and print, a metallized layer or aluminum foil for barrier, and a sealant layer for heat sealing. Specify the complete structure instead of relying on the search term alone.
Metallized PET deposits a thin aluminum layer on film and offers strong barrier at lower cost and weight, with better flex-crack tolerance in many constructions. Aluminum foil laminate provides the highest barrier and full opacity but can crack at flex points and costs more. The right choice depends on the product's sensitivity, target shelf life, distribution handling, and budget—confirmed with the exact structure rather than assumed from the bag's appearance.
Barrier level, food-contact suitability, seal performance, and any shelf-life or protective claim depend on the complete laminate, the product, filling and sealing conditions, and storage—not the word mylar. Products in regulated categories additionally require market-specific compliance review. Request structure documentation and validate with product-filled testing where shelf life matters.
Provide the product, bag format and dimensions or fill weight, barrier and shelf-life target, closure and features, print and finish, quantity for each size and artwork, sample needs, and target timing. Digital printing can support lower quantities and multi-SKU programs; flexographic and gravure routes are reviewed for larger repeat volumes.
Packaging Knowledge Center
Use these practical articles to prepare specifications, identify project risks, and ask better questions before sampling or production.
Food-contact suitability depends on the complete laminate, the sealant layer, inks and adhesives, and the intended application—not on the mylar name. Request food-contact documentation for the exact structure and confirm suitability for the product, filling conditions, and storage.
Mylar refers to the PET film base; the barrier usually comes from a metallized layer or a laminated aluminum foil layer. Metallized PET offers strong barrier at lower cost and weight, while foil laminate provides the highest barrier and full opacity at higher cost and lower flex-crack tolerance. The exact structure should be specified rather than inferred from appearance.
High-barrier metallized and foil laminates substantially reduce aroma transmission compared with clear films, but odor performance depends on the complete structure, seals, closure, and the product itself. Applications with specific odor-control requirements should be validated with the exact bag and product.
MOQ varies by bag dimensions, structure, print route, and quantity per artwork. Digital printing can reduce setup requirements for lower quantities and multi-SKU programs, while flexographic and gravure routes generally suit larger repeat orders. Quantities are confirmed at quotation.
Yes, where the format supports it. Press-to-close zippers and slider concepts can be added to suitable formats, and plain heat-seal bags can be resealed with an impulse sealer. Closure choice, placement, and performance are confirmed with the complete bag specification.