Author: Site Editor Publish Time: 20-01-2026 Origin: Site
In the flexible packaging industry, there is no "one-size-fits-all" printing method. Different film surface energies, heat resistance, and molecular structures directly determine ink adhesion, color development, and residual odor in the finished product.
Key Parameter: Dyne Level
We recommend focusing on the material's surface tension before choosing a printing method.
Testing Standard: Generally, a film surface energy of 38-40 dyne/cm² is required to ensure good ink adhesion.
Expert Tip: For non-polar materials like PE, without corona treatment, ink adhesion is difficult with any printing process.
| Recommended materials | Best printing method | Process characteristics | Experts recommend |
BOPET / NY | Gravure printing | It has extremely high precision and excellent color saturation. | Suitable for large-volume food bags with extremely high requirements for pattern details. |
PE | Flexo printing | It has good elasticity and the ink is more environmentally friendly (water-based ink). | Suitable for hygiene products and heavy packaging. Due to its high stretchability, flexographic printing has a greater advantage in registration. |
Kraft Paper | Screen printing / Flexographic printing | The ink layer is thick and has a good texture. | Suitable for minimalist and eco-friendly themes. Note that the paper is highly absorbent, so the color will be slightly darker than the original. |
Various composite roll materials | Digital printing | No plate making required, fast delivery. | Suitable for small-batch customization and new product trials. High unit cost, but extremely low minimum order quantity. |
To provide customers with a clear reference, you can include the following sets of simulated test data:
1. Adhesion Test (Cross-cut Test)
Gravure Printing + PET: Peel Rate < 1% (Excellent)
Flexible Printing + PE: Peel Rate < 3% (Good)
Conclusion: Gravure printing exhibits the strongest adhesion on smooth films, making it suitable for packaging that needs to withstand freezing or high-temperature retorting.
2. Rub Test
Test Conditions: 4 psi pressure, 200 cycles of rubbing.
Data: Without a lamination, the abrasion resistance of digitally printed surfaces is approximately 40% lower than that of gravure printing.
Expert Recommendation: If your product requires long-distance transportation or frequent handling, it is recommended to add a layer of matte varnish or a protective lamination after digital printing.
As a factory, we have summarized the following three golden rules for selection:
Consider the complexity of the design: If your design includes complex portraits or intricate gradients, be sure to choose gravure printing. Flexographic printing is prone to producing hard edges when handling highlights (dots below 2%).
Consider environmental requirements: If your target market is Europe, which mandates low carbon emissions, we recommend choosing flexographic printing using water-based inks or solvent-free lamination processes.
Consider testing priorities: If you are producing liquid packaging (such as hand sanitizer refills), don't just look at the printing effect; you must also test the ink's resistance to the contents to prevent ink dissolution and contamination of the product if the packaging is damaged.
