Retort bags and Mylar bags are both types of flexible packaging, but they have different properties, materials, and applications

Here’s a comparison chart highlighting the key differences between retort bags and Mylar bags

Feature	Retort Bags	Mylar Bags
Primary Purpose	Sterilizing and preserving wet/moist foods (e.g., soups, pet food).	Long-term storage of dry goods (e.g., grains, coffee) via oxygen/light barrier.
Material Layers	Multi-layer: Polyester + aluminum foil + nylon + heat-resistant polypropylene.	Typically 3 layers: Polyester (Mylar®) + aluminum foil + polyethylene.
Heat Resistance	Withstands high-heat sterilization (up to 240°F/116°C).	Not heat-resistant unless labeled “retortable” (standard bags melt under high heat).
Applications	Wet foods, medical supplies, ready-to-eat meals.	Dry goods, electronics, dehydrated foods, emergency supplies.
Sterilization Process	Designed for retort processing (steam/pressure sterilization post-sealing).	No sterilization; relies on oxygen absorbers + sealing for preservation.
Sealing Requirements	Heavy-duty seals to withstand retort pressure and heat.	Standard heat or vacuum sealing (no pressure resistance needed).
Shelf Life	2–5+ years (sterilized, wet contents).	1–20+ years (dry goods with oxygen absorbers).
Cost	Higher (specialized materials and manufacturing).	Lower (standard barrier materials, unless customized).
Flexibility/Thickness	Thicker, rigid structure for durability during retort.	Lightweight, flexible, space-efficient.
Key Advantage	Safe for wet, acidic, or fatty foods requiring sterilization.	Superior oxygen/light/moisture barrier for dry goods.