01
A specification is the agreement behind the package
A flexible package is the result of several systems working together. The material has to protect the product. The sealant has to respond to the production process. Finished dimensions have to provide usable volume and fit the line. Graphics have to align with seams, folds, repeats, and registration. The finished package then has to survive handling, distribution, storage, and consumer use.
A specification brings those requirements into one controlled record. It should be detailed enough to reduce avoidable interpretation, but it should not freeze assumptions that have never been tested. When a value is still open, identify the owner and the evidence needed to close it.
02
Develop the package in the right order
Start package development with the product, target fill, package format, filling method, equipment, headspace, seals and closures, distribution, and consumer use. Finalize the dimensions, materials, and graphics after those requirements are clear.
The order matters because each decision changes the next one. Product behavior affects usable volume and the seal area. The filling process affects opening, headspace, and sealant needs. Package geometry controls the dieline and available print area. Resolving those inputs first reduces avoidable redesign, material changes, and production surprises.
| Decision | Questions to resolve before moving forward |
|---|---|
| Product and use | What is being packed, how much, what can affect product quality, and how will the consumer open, dispense, or reclose it? |
| Production | Who will fill it, on what equipment, by what method, and under which forming and sealing conditions? |
| Format and size | Which package style fits the use and line, and how much usable space, headspace, and clean sealing clearance are required? |
| Materials and features | What protection, toughness, stiffness, sealing, closure, and product-contact functions must the package provide? |
| Graphics and approval | Which dieline, print method, validation evidence, acceptance criteria, and approval owners control the release? |
03
1. Define what the product asks of the package
The product establishes the protection and compatibility problem. Start with actual conditions, not a favorite material structure.
Product identity
Formulation or product family, physical form, particle shape, oils, aromas, solvents, acids, active ingredients, and known sensitivities.
Target fill
Net weight or volume, density or bulk density, settling behavior, dose variation, and whether the product is filled hot, warm, cold, frozen, or ambient.
Shelf-life objective
Target duration, acceptable product change, storage environment, distribution region, and whether validation already exists.
Protection pathways
Oxygen, moisture, light, aroma loss or ingress, grease, chemical interaction, puncture, abrasion, flexing, and temperature cycling.
Consumer use
Opening, reclosing, dispensing, portioning, visibility, tamper evidence, child resistance where required, and expected reuse after opening.
04
Define the role of the primary and secondary packages
Barrier requirements should be evaluated across the complete packaging system. The package that provides presentation, grouping, or convenience does not always need to provide the product’s primary barrier.
For example, a chocolate bar may be wrapped in a cold-seal film that provides the necessary product protection and then placed inside an outer pouch. If the individual bar wrap already provides the required barrier, the outer pouch may not need the same barrier performance. Its structure can instead be designed around containment, appearance, handling, and consumer use.
The role of each package should be defined before materials are selected because protection may come from the primary package, the secondary package, or a combination of both.
05
Choose the format for the production system and consumer
Choosing between a premade pouch and roll stock should be based on the full production system. The decision depends on available filling equipment, production volume, package features, changeover needs, product behavior, seal requirements, and how the consumer will use the package.
A resealable stand-up pouch may be appropriate when shelf presentation and repeated use matter. A form-fill-seal package made from roll stock may be better suited to an established automated filling line. The package must fit the product, operation, and customer experience.
06
2. Record how the package will be made and filled
Production requirements often decide whether a theoretically suitable material is usable. Confirm the equipment and operating window with the people who run the line. A brand drawing or an old purchase order may not capture change parts, seal geometry, roll limits, registration needs, or the way dimensions are measured on the equipment.
| Area | Information to control |
|---|---|
| Premade pouches | Finished dimensions and tolerances, seal widths, gusset, zipper or fitment, opening, fill direction, top-seal allowance, pouch count and pack-out |
| Roll stock | Web width, repeat, unwind, eye mark, core, maximum roll diameter and weight, splice rules, roll build, print lanes and registration tolerances |
| Filling and sealing | Equipment type, speed range, forming geometry, product drop, seal temperature, pressure and dwell, contamination risk, cooling and handling after seal |
| Forming webs | Cavity drawing, draw depth, corner radii, plug assist, forming temperature, cycle, gauge distribution and compatibility with the top web |
07
3. Translate requirements into the package definition
Format and geometry
Package style, finished dimensions, tolerances, seals, gussets, folds, features, fitments, usable fill area and intentional headspace.
Material construction
Each layer or component, nominal gauge or basis weight, treatment, adhesive or tie layer where controlled, print location, sealant, coatings and functional purpose.
Performance
Barrier values with conditions, seal strength or peel target, hot-tack need, puncture or impact requirement, coefficient of friction, stiffness, shrink or forming behavior, and product compatibility.
Graphics
Print process, color targets, ink system, surface or reverse print, opacity, finish, overprint protection, repeat, distortion, eye marks, barcodes and approved artwork revision.
Packing and shipment
Count, winding and roll identification, bagging, cartons, pallet pattern, storage limits, certificate requirements, lot traceability and retention samples.
08
Release the dieline before production artwork
Artwork should be finalized only after the package dimensions, format, seals, folds, gussets, zipper location, and other structural features are established. These elements determine the usable print area and where important graphics, instructions, barcodes, and regulatory information can be placed.
For example, artwork created before a stand-up pouch is sized may place a logo across a gusset, a barcode near a seal, or required copy below the zipper. Establishing an accurate dieline first reduces rework and helps the finished package appear as intended.
09
4. Define how the package will be approved
Samples and prototypes can help evaluate size, appearance, opening, filling access, and general package function. They may not fully represent production materials or production-line performance.
Final approval should account for the intended film structure, converting process, filling equipment, sealing conditions, and actual product. When a full production trial is not practical, the first production run should be planned with clear specifications, inspection criteria, and coordination among the brand, Packaging HQ, and the co-manufacturer.
- Confirm the specification inputs and identify every open decision.
- Review drawings, material proposal, artwork geometry, and production requirements with the brand and co-manufacturer.
- Use prototypes or filled samples to check size, features, handling, and consumer interaction. A mockup does not validate the production material.
- Run compatibility, barrier, seal, distribution, and line trials appropriate to the application.
- Record the test conditions, sample identities, results, deviations, and approval owners.
- Release a controlled specification and establish which future changes require notification, qualification, or reapproval.
10
5. Protect the approved result with change control
Flexible packaging can change even when the commercial description appears unchanged. Resin, sealant, adhesive, ink, treatment, layer gauge, manufacturing location, equipment, or test method may influence performance. The specification should define the controlled characteristics and the notification expected before a change is introduced.
Change control should also cover brand-initiated changes. A new fill weight, faster line speed, different co-manufacturer, altered zipper location, shorter seal dwell, or revised shelf-life target can require package review even when the material is not intentionally changing.
11
Bring the co-manufacturer into development early
When a co-manufacturer or co-packer will fill the package, they should be involved before the specification is finalized. Their equipment, forming limits, sealing system, preferred roll configuration, package handling, inspection process, and operating experience can affect both the structure and dimensions.
A package may protect the product and look correct but still create production problems if it does not fit the filler’s equipment or process. With the brand’s permission, Packaging HQ can work directly with the brand and co-manufacturer to confirm requirements and resolve open specifications before production.
FIELD CHECKLIST
Information to collect
Use this as a working prompt, then adapt the final specification or validation plan to the actual application.
- Product, formulation family, fill weight or volume, and density
- Shelf-life objective and the failure pathways the package must control
- Package format, finished dimensions, seals, gussets, and features
- Equipment, filling method, line speed, forming, and sealing conditions
- Material structure with the intended function of each layer
- Barrier and mechanical requirements with test conditions
- Print, artwork, registration, finish, and barcode requirements
- Roll or pouch packing, identification, shipment, and storage requirements
- Validation plan, acceptance criteria, and approval owners
- Revision history and supplier/customer change-notification expectations
COMMON QUESTIONS
Questions worth resolving
Who should own the flexible packaging specification?+
Ownership should be explicit. The brand often owns the commercial and product requirements, the co-manufacturer owns critical line constraints, and the packaging supplier defines the manufactured material or package. One controlled record and named approval owners keep those responsibilities connected.
When should artwork begin?+
Concept work can begin early, but production artwork should use a released dieline or web layout after package geometry, seams, gussets, features, repeat, unwind, distortion, and required print-free areas are confirmed.
Does the secondary package need the same barrier as the primary package?+
Not necessarily. Barrier should be assigned across the complete packaging system. If the primary package already provides the required product protection, the secondary package may be designed mainly for containment, presentation, handling, or use. Confirm whether storage and distribution conditions require it to add protection.
Is a prototype enough to approve production?+
A prototype can help assess size, appearance, opening, and handling, but it may not represent production materials or line performance. Use the best evidence available for approval and state what still needs to be verified during a trial or controlled first production run.
REFERENCES & TEST METHODS
Test methods and acceptance criteria should be selected for the actual application. These standards and technical sources support the principles discussed in this guide:
FDA: Container Closure Systems for Packaging Human Drugs and Biologics↗ASTM F88/F88M: Seal Strength of Flexible Barrier Materials↗ISTA: Packaged-Product Test Procedures↗GS1 General Specifications: Symbol Placement Guidelines↗