Date: Dec 25 2025 from: StarColor Ink Views:
Gravure reverse printing ink and flexo water-based ink are the two mainstream water-based ink systems used in flexible packaging. Although both belong to environmentally friendly water-based inks, their formulation logic, performance characteristics, and application boundaries differ significantly due to fundamental printing process differences.
For printing engineers and packaging buyers, accurately understanding these differences is essential for achieving precise matching between printing process, ink system, and substrate. This article analyzes the differences across eight core technical dimensions.
Designed specifically for gravure reverse printing, this ink must fill deep gravure cells (50–150 μm) and transfer a large ink volume. After doctor blade wiping, the ink is printed on the inner layer of packaging films. Key requirements include high filling ability, strong opacity, and fast drying.
Flexo printing relies on anilox rollers with shallow cells (30–80 μm) and precise ink metering. The ink must have low viscosity, excellent rheology, and shear-thinning behavior to ensure smooth transfer under low printing pressure without clogging.
Conclusion: These two inks are not interchangeable. Cross-use often leads to clogging, uneven ink films, and poor adhesion.
Gravure Reverse Printing Ink: Primarily uses polyurethane-acrylate composite resins (35–45%), offering dense ink films (8–12 μm), high opacity, and excellent resistance to heat and oil. High-end formulations may include 10–15% polyamide resins for improved adhesion on BOPP and PET films.
Flexo Water-Based Ink: Mainly based on waterborne acrylic resins (25–35%) with lower molecular weight (8,000–15,000), resulting in lower viscosity (15–35 s, Zahn #4, 25°C) and superior flow properties.
Gravure inks use medium particle-size pigments (1–3 μm) with higher inorganic pigment content (20–30%) to ensure opacity. Fillers such as calcium carbonate (5–8%) may be added for abrasion resistance.
Flexo inks require fine pigments (0.5–2 μm) to avoid anilox clogging. Filler content is usually limited to ≤3%, resulting in thinner ink films (3–6 μm).
Gravure inks emphasize fast-drying agents, defoamers, and adhesion promoters. Flexo inks focus on leveling agents, antistatic additives, and retarders to maintain stable printing.
| Property | Gravure Reverse Ink | Flexo Water-Based Ink |
|---|---|---|
| Viscosity (Zahn #4, 25°C) | 25–50 s | 15–35 s |
| Ink Film Thickness | 8–12 μm | 3–6 μm |
| Retort Resistance (121°C / 30 min) | Excellent | Limited (special grades only) |
| Oil Resistance | Excellent (72h no migration) | Moderate |
Gravure printing requires precise doctor blade pressure control and staged drying. Flexo printing focuses on anilox selection and viscosity stability during high-speed production.
Ink Cost:
Gravure reverse ink: USD 4.9–6.9 / kg
Flexo water-based ink: USD 3.5–4.9 / kg
Equipment Investment:
Gravure press: USD 210,000–420,000
Flexo press: USD 110,000–210,000
The differences between gravure reverse printing ink and flexo water-based ink stem directly from their respective printing processes. Understanding these differences enables precise matching between ink, process, substrate, and packaging requirements.
As sustainability regulations tighten, both ink systems continue evolving toward low migration, high solid content, and energy-efficient drying technologies.