Prevent shrink sleeve cracks and flakes with Flint Group’s Shrink Whites
Whether it’s decorating bottles or other complex container geometries, shrink sleeves are unmatched in their ability to deliver 360-degree standout graphics. However, achieving the flawless appearance that brand owners expect post-application depends on a critical – but often overlooked – ingredient: the white ink foundation.
In any shrink application, the white layer performs multiple roles. It provides a solid foundation that delivers opacity and contrast on clear films, masks the container, and stabilises color reproduction across SKUs and substrates. However, it must also withstand the high heat, moisture, and physical stress of the shrink process. If the ink film cannot deform and recover in line with the substrate, it risks stress whitening, micro-cracking, flaking, or distortion in the highlight areas, which compromise both shelf impact and brand integrity.
Why inks fail under stress
The most critical zones in any shrink sleeve are the high-shrink regions, where local deformation can be most severe. In these areas, it is essential that white inks maintain adhesion and integrity even as the substrate deforms during shrinkage. If the cured ink is too brittle, internal stresses concentrate at these points, causing cracking or flaking that can damage the printed design.
Introducing Flint Group’s Shrink Whites
Flint Group’s new shrink whites, UEK91116 and UEK91117, under the EkoCure® XS ink series, are specifically designed to address these pain points in narrow web shrink sleeve production. These inks are engineered to maintain a coherent, flexible ink film throughout the shrink process, even in the most demanding conditions. At the same time, their adhesion profile is tuned for shrink sleeve substrates, supporting robust performance in standard tape and crinkle tests without the need to strip or remove ink before shrink. The result is a smooth, continuous white surface after maximum shrink, providing a reliable foundation for process colors and special effects.
Dual cure capability
A key attribute of the new EkoCure XS shrink whites is their dual-cure capability, ensuring consistent performance under both UV LED and conventional mercury-curing systems. For converters, this means a single white platform can be specified across mixed curing environments, simplifying inventory and facilitating smoother transitions as presses are upgraded to UV LED.
Dual-cure chemistry also contributes to process robustness. By design, the system cures efficiently across the relevant wavelength range, supporting high line running speeds while maintaining through-cure and flexibility. This helps converters reduce the risk of under-cure in heavy laydowns or low-energy areas, while avoiding the brittleness associated with over-exposure. These benefits translate into stable performance, fewer on-press adjustments, and more consistent shrink results across jobs and plants.
Integration with toolbox ink systems
Flint Group shrink whites have been developed to work seamlessly in combination with toolbox ink systems, allowing converters to build a full EkoCure XS-compatible portfolio around a common white base. This compatibility supports efficient color matching when running complex ink sequences or adding functional coatings.
By integrating these shrink-optimised whites into a toolbox approach, converters can standardise on a platform that covers a broad range of shrink sleeve requirements while maintaining the flexibility to tailor colors, coatings, and effects as needed. In doing so, they gain both the mechanical performance required for demanding shrink applications and the process control needed for high-quality, repeatable production.
Reducing problems, not print performance
White inks are central to maximizing print quality and production efficiency. Cracks and flakes in shrink sleeve printing increase wasted time and material, ultimately leading to quality concerns among converters and brand owners. By addressing the root causes in the ink film’s chemistry and curing behavior, Flint Group’s new EkoCure XS shrink whites give printers a more resilient, predictable foundation for demanding shrink work.