Start with the product
The product decides the structure. Coffee needs an oxygen barrier and a one-way degassing valve to release carbon dioxide without letting air in. Snacks need moisture and grease resistance. Pet food needs strong seals and puncture resistance. Tea needs aroma retention and light blocking. Before choosing a material, write down what will destroy the product: oxygen, moisture, light, heat, or physical damage. That list becomes your barrier specification.
Shelf life targets matter too. A six-month ambient shelf life needs less barrier than a two-year one. Distribution conditions matter as well. A pouch that travels by sea container in summer faces different stress than one sold locally. Buyers who define shelf life and distribution early avoid over-specifying or under-specifying the laminate.
Common material structures
Most flexible packaging uses a laminate of two or more layers. PET/AL/PE combines polyester, aluminium foil, and polyethylene. The foil gives an excellent oxygen and moisture barrier, which suits coffee and sensitive foods. PET/NY/PE uses nylon instead of foil, giving good puncture resistance and flex crack resistance, useful for frozen or vacuum applications. Kraft paper laminates offer a natural look and moderate barrier.
Mono-material PE and PP recyclable structures are growing as brands respond to packaging waste rules. They usually provide a lower barrier than foil laminates, so they suit shorter shelf life or products that are less oxygen sensitive. PLA/PBS compostable options exist for industrial composting streams. Degradable options are also available, but buyers should check local definitions because degradable, biodegradable, and compostable are not the same claim.
Barrier and add-ons
Barrier is not only about the film. Every add-on changes performance. A zipper creates an opening that can let air in after first use. A window removes a patch of barrier material. A spout and cap add a leak point. A one-way degassing valve is essential for roasted coffee but unnecessary for dry snacks. Tear notches and hang holes do not affect barrier, but they affect how the pack runs on filling lines.
Test the full pack, not just the film. Oxygen transmission rate and water vapour transmission rate are measured on flat film, but a finished pouch has seals, corners, and closures. Ask for shelf life testing on the actual filled pack when the product is sensitive. This is standard practice and prevents expensive reformulation later.
Filling and format
The filling method narrows the format. Flat bottom pouches stand on the shelf and hold more weight, which suits coffee and pet food. Stand up pouches work well for snacks and smaller retail packs. Flat and three-side-seal pouches run efficiently on horizontal form fill seal machines. Spout pouches, including corner spout and STANDCAP, suit liquids, sauces, and purees. Side gusset bags give a traditional look for tea and coffee. Rollstock film is the choice for high-speed vertical form fill seal lines.
Consider the filling line before finalising the artwork. Seal width, film thickness, and coefficient of friction affect machine speed and seal quality. A structure that runs perfectly on one filler may jam on another. Send a sample of the intended film or pouch to the filling line for a trial when possible. This is a common step for contract manufacturers and co-packers.
Cost drivers and print
Unit cost depends on material, structure, print method, and order quantity. Digital printing makes sense for low MOQ: from 100 pcs for pouches and 10 kg for film. Rotogravure printing becomes economical at higher volumes: from 10,000 pcs or 200 kg. Rotogravure offers up to 10 colours and lower unit cost at scale. Digital print runs typically ship in 10-15 working days after artwork approval. Rotogravure runs take 20-25 working days.
Other cost drivers include the number of layers, the type of barrier, and add-ons such as valves, zippers, spouts, and handles. Freight and duties also affect landed cost. Buyers should compare total landed cost, not just unit price. A slightly higher film price with better machine runnability can lower the cost per finished pack.
Mistakes to avoid
Common mistakes include choosing a structure before defining shelf life, ignoring how add-ons affect barrier, and ordering artwork before confirming the filling line. Another mistake is assuming a recyclable or compostable claim will be accepted everywhere. Rules differ by country and municipality. Check local guidelines and ask the manufacturer for documentation.
Skipping a fill trial on the actual line. - Forgetting that zippers and windows reduce barrier. - Using foil when a lower barrier would do. - Ordering rotogravure before the design is final. - Assuming all compostable films break down in home compost.
A short technical brief saves time. Include product type, shelf life, distribution, filling method, and any sustainability targets. That lets the supplier recommend a structure, print method, and MOQ that fit the project instead of guessing.