How to Choose Flexographic Inks for Food Packaging

Date: Nov 14 2025   from: StarColor Ink  Views:

Flexographic printing has become a leading technology for food packaging—such as snack bags, beverage labels, and frozen food boxes—due to low equipment investment, wide substrate compatibility, and strong environmental performance. It now accounts for approximately 62% of all food packaging printing.

However, the “direct food contact” nature of many packages, combined with the “high-speed, low-pressure” characteristics of flexographic printing, requires inks to meet three strict expectations: safety & migration compliance, performance adaptability, and cost efficiency. A portion of inks marketed as “food-grade” still fail at high-temperature applications or show migration levels above regulatory limits. Others are environmentally compliant but dry slowly, restricting production speed.

1. Core Selection Principles

The selection of flexographic inks for food packaging should avoid the narrow mindset of “only checking price” or “only checking eco-labels.” Two core principles must be followed:

• Regulatory compliance is the bottom line. Any ink component that migrates into food poses both health risks and legal consequences.
• Application matching ensures efficiency. Different foods and substrates require different levels of heat resistance, oil resistance, and adhesion. Proper matching directly affects waste rate and production stability.

2. Key Dimension 1: Compliance & Certification

1) Match certifications to food-contact type

• Direct food contact: Must meet GB 4806.14-2023, including:
  • Total migration ≤ 10 mg/dm²
  • Heavy metals ≤ 1 mg/kg
  • Aromatic amines ≤ 0.01 mg/kg
  • No detectable benzene/toluene

  For export packaging, inks should also comply with FDA 21 CFR 175.300 and EU 10/2011, including specific migration limits ≤0.01 mg/kg.

• Indirect food contact:
  • Follow GB 38507-2020 (VOCs ≤ 100 g/L; water-based recommended ≤ 50 g/L)
  • Ensure anti-penetration performance

2) Verify authenticity of certificates

Important checks:

• Issued by accredited labs (CNAS/CMA, SGS, Intertek)
• Clearly labeled as flexographic ink, not generic ink
• Validity ≤ 6 months and includes full migration testing

3) Watch for hidden risky ingredients

• Plasticizers (phthalates ≤ 0.1% per EU & CA Proposition 65)
• Photoinitiator residues in UV flexo inks (≤0.6 mg/kg)
• Odor performance: must remain non-irritating after 24h at 40°C

3. Key Dimension 2: Performance Adaptation

1) Base performance for flexographic systems

• Adhesion: Should reach 4B–5B per cross-hatch test (GB/T 9286)
• Viscosity: Stable at 25–35 seconds (#4 cup, 25°C)
• Drying speed:
  • Water-based: surface dry within 2–3 sec at 40–60°C
  • UV flexo: full cure within 0.5 sec (80–120 mJ/cm²)
• Color stability: ΔE ≤ 0.8; dot gain ≤ 8%

2) Scenario-specific performance

• Hot-fill / hot-food packaging: Tg ≥ 50°C; no softening at 70°C
• Oil-rich foods: Oil resistance ≥ Grade 5 (ASTM D1653)
• Frozen foods: Elongation ≥18%; no cracking after -20°C freeze–thaw
• Acid/alkaline foods: Resistant to 3% acetic acid or 1% NaOH for 24h

4. Key Dimension 3: Cost Evaluation

1) Beware of “low solids, high consumption” inks

Low-cost inks often have solid content of only 30%. This increases consumption by 30%+ and slows drying, reducing speed by 15–20%.

2) Include hidden costs

• Testing costs: USD 150–300 per batch for compliant inks; non-compliant batches can exceed USD 1,500 in retesting and delays.
• Waste costs: Poorly matched inks may cause 10–15% waste. Quality inks typically achieve ≤3%, saving USD 7,000+ monthly for a one-million-m² factory.
• Environmental system cost: High-VOC inks require RTO systems; low-VOC water-based inks generally require only activated carbon.

3) Cost-effective option: Export-oriented Chinese brands

For export packaging, companies such as Zhongzhixing (brand: Starcolor) offer high-performance, certified water-based flexographic inks featuring:

• VOCs ≈ 10 g/kg
• 48% solid content
• FDA & EU 10/2011 compliance
• 20–30% lower cost compared to Western brands
• English SDS + customs documents
• Delivery in 2–3 weeks

5. Key Dimension 4: Service & Technical Support

• Custom colors and on-site technical support
• Supply chain reliability (annual ink capacity ≥ 5,000 tons)
• Traceability and warranty (one-year quality guarantee)

6. Practical Selection Workflow

1. Define requirements (food type, substrate, export region)
2. Verify certifications
3. Conduct on-machine testing
4. Evaluate cost + service + stability

Conclusion

Choosing flexographic inks for food packaging requires a balanced approach centered on compliance, performance, cost, and service. By selecting reputable suppliers—such as Zhongzhixing and its Starcolor brand—converters can reduce compliance risks, improve efficiency, and achieve both environmental and economic benefits.