Colour Control Challenges in Flexible Packaging

Flexible packaging - printed films, laminates, pouches, sachets, and flexible lidding materials - presents some of the most demanding colour management challenges in the entire printing and packaging industry. The combination of process variability, substrate complexity, and the high stakes of food safety and brand compliance creates an environment where colour measurement is not just a quality improvement tool - it is a production necessity.

The primary printing process for flexible packaging is flexographic printing - a process that uses flexible relief plates, fluid ink systems, and continuous web substrates. Flexographic colour management is inherently more complex than offset printing because the inks are formulated to dry by evaporation or UV curing rather than by absorption into the substrate, and the colour outcome is sensitive to viscosity, temperature, anilox cell volume, impression pressure, and the chemical properties of the specific film or laminate substrate. Each of these variables interacts with the others, creating a multidimensional system that must be measured and controlled systematically to produce consistent colour.

Substrate variability compounds the challenge. Flexible packaging films vary in surface energy, optical characteristics, and dimensional stability in ways that affect how ink adheres and how it looks after printing. A colour specification tested on one batch of film may produce measurably different results on the next batch from the same supplier, because film properties vary within manufacturer tolerances in ways that affect colour outcome. This raw material variability must be detected through incoming measurement and managed through ink adjustments or process compensation - a cycle of measurement, analysis, and correction that depends entirely on having reliable, calibrated instruments at the ready. The eXact 2 spectrophotometer is the standard measurement tool for flexographic press-side colour control, and the full X-Rite range is available through Seaga Group.

The Role of Anilox and Ink Viscosity

In flexographic printing, the anilox roller - a precision-engraved roller that meters ink to the printing plate - is a critical variable in colour control. Different anilox cells deliver different volumes of ink per unit area, and as anilox cells wear with use, the ink volume they deliver decreases. This gradual reduction in ink delivery changes the colour density on press, causing colour to drift progressively over time. Systematic measurement of colour using a spectrophotometer detects this drift as it begins, allowing the press operator to compensate - adjusting ink viscosity, changing to a different anilox specification, or scheduling anilox cleaning or replacement.

Ink viscosity is equally important. Flexographic inks thin with temperature and thicken as solvent evaporates into the press atmosphere. Both viscosity changes affect the ink film on the substrate, which affects colour. Press operators managing viscosity manually make adjustments based on viscosity measurement rather than colour measurement - but viscosity changes produce colour changes, and colour measurement with an eXact spectrophotometer provides the direct feedback needed to verify whether viscosity management is keeping colour within the specification.

Brand Colour Compliance in Flexible Packaging

Flexible packaging produced for branded consumer goods must meet the same brand colour compliance requirements as any other packaging format - with Delta E tolerance specifications against Pantone or LAB standards, and documented measurement evidence of compliance. For packaging converters producing flexible film for food, household, and personal care brands, this compliance requirement is typically contractual - failure to meet it triggers rejection and replacement at the converter's cost.

The measurement workflow for flexible packaging colour compliance follows the same structure as for other printing processes: measure against stored brand colour standards at makeready and at regular intervals during the run, compare ΔE against the agreed tolerance, adjust if necessary, and document the measurement history. Color iQC software manages this workflow systematically, generating the compliance reports that brand owners and their packaging buyers expect from approved suppliers.

For flexographic converters supplying multiple brand accounts simultaneously - running several different jobs through the press system in a shift - the ability to manage multiple colour standards efficiently within a single measurement workflow is a practical requirement. X-Rite instruments support this multi-standard workflow, allowing operators to switch between job colour targets quickly and maintain the measurement discipline needed for each brand account concurrently.

Conclusion

Flexible packaging colour management is one of the most technically demanding applications for X-Rite measurement technology - demanding because of the process complexity of flexographic printing, the raw material variability of packaging films, and the commercial consequence of compliance failures for major brand accounts. X-Rite spectrophotometers and quality management software provide the measurement infrastructure needed to manage colour consistently in this demanding environment, enabling flexible packaging converters to meet tight brand colour specifications, document compliance professionally, and build the supplier credentials that win long-term contracts with major packaged goods manufacturers.