Every flexible pack is built from one or more layers of film, and each layer does a job: barrier, strength, sealability, printability, or sustainability. The material structure is what protects your product, holds your print, and runs cleanly on your line. This page explains how flexible packaging materials are put together and the films we work with, so you can match the right structure to your product without paying for barrier you do not need.
Layers, not just plastic
Flexible packaging is rarely a single material. Most pouches and films are laminates, meaning two, three, or more thin layers bonded together, each doing something the others cannot. A three-layer laminate, for example, might pair a printable outer film, a barrier middle layer, and a food-safe sealing layer. Combining layers lets us build a pack that is light, strong, and protective at the same time, tuned to what is inside.
- Outer layer: carries the print and gives the pack its finish and stiffness.
- Barrier layer: blocks oxygen, moisture, light, or aroma to protect freshness and shelf life.
- Sealant layer: the inner food-contact film that heat-seals the pack closed.
Two ways we build a structure
Laminated structures bond separate films together with adhesive or heat, so you can combine the best film for each job into one material. Co-extruded (COEX) films form multiple polymer layers in a single step, extruded together without a separate bonding stage. Both approaches let us tune barrier, strength, and seal performance; the right choice depends on your product, shelf life, and budget.
Common material structures
The number of layers is driven by how much protection your product needs.
- Single-layer films: economical, used where barrier demands are low, such as some overwraps and short-life items.
- Two-layer laminates: a printable film bonded to a sealant, common for dry goods.
- Three-layer laminates: the workhorse of flexible packaging, adding a dedicated barrier layer for longer shelf life and tougher products.
- High-barrier multi-layer laminates: extra barrier and strength layers for demanding products such as coffee, pet food, and moisture or oxygen sensitive goods.
Flexible packaging materials at a glance
These are the films most often used in flexible packaging laminates, and the job each one does best. We combine them into a structure sized to your product, so you get reliable barrier, clean seals, and high-quality print.
| Film / material | What it is | Barrier strengths | Recyclable | Typical role |
|---|---|---|---|---|
| PET (polyester) | Strong, heat-stable polyester film | Good stiffness and print, moderate oxygen and moisture barrier | Yes (PET stream) | Printable outer layer |
| BOPP | Biaxially oriented polypropylene | Clear and glossy, good moisture barrier, low oxygen barrier | Yes (PP stream) | Clear outer layer |
| OPP | Oriented polypropylene | Clarity and stiffness, moisture resistance | Yes (PP stream) | Outer layer |
| CPP | Cast polypropylene | Excellent heat seal and clarity | Yes (PP stream) | Inner sealant layer |
| LDPE / LLDPE | Low and linear low density polyethylene | Strong, reliable heat seals and good moisture barrier | Yes (PE stream) | Sealant layer |
| HDPE / MDPE | Higher density polyethylene | Added stiffness and moisture barrier | Yes (PE stream) | Sealant and mono-material structures |
| Nylon (PA) | Polyamide film | Tough and puncture resistant, good oxygen barrier | Stream dependent | Strength and barrier middle layer |
| EVOH | Ethylene vinyl alcohol | Excellent oxygen and aroma barrier | Stream dependent | High-barrier middle layer |
| PVDC | Polyvinylidene chloride coating | High barrier to oxygen, moisture and aroma | No | Barrier coating |
| Metallised PET / OPP (metPET, metOPP) | Film with a fine vacuum-deposited metal layer | Strong barrier to light, oxygen and moisture at low weight | Stream dependent | Barrier layer, lower cost than foil |
| Aluminium foil | Thin aluminium layer | Highest barrier to light, oxygen, moisture and aroma | No (kerbside) | Maximum-barrier layer for long shelf life |
| KPET | PVDC-coated PET | High oxygen and moisture barrier with print strength | No | High-barrier printable layer |
| COEX | Co-extruded multi-polymer film | Combines several polymers in one film | Stream dependent | Multi-function single film |
| PLA | Plant-based polylactic acid | Renewable, compostable under the right conditions | Compostable | Sustainable structures |
| Recyclable mono-material (PE or PP) | Single-polymer laminate | Balanced barrier designed to stay in one recycling stream | Yes | Recycle-ready packaging |
Sustainable material options
Material structure is also where sustainability decisions are made. We offer recycle-ready mono-material structures designed to fit kerbside and store-drop-off streams, structures that incorporate recycled content, and guidance on meeting APCO 2025 targets, all without giving up the barrier your product needs. We will talk you through the trade-offs so your pack is both fit for purpose and closer to your environmental goals.
Not sure which structure is right for your product?
Talk to our team and we will match the right material structure to your product, shelf life, and line.
