Security inks are specially engineered printing inks containing functional materials that create visible or machine-readable security effects. They are widely used to protect ID cards, government documents, banknotes, tax stamps, and branded packaging from counterfeiting.
By incorporating optical, thermal, fluorescent, or magnetic technologies, security inks provide clear authentication methods and significantly increase the difficulty of reproduction.
1. Optically Variable Ink (OVI)
OVI utilizes optically variable pigments to produce two distinct colors when viewed from different angles or under varying lighting conditions (e.g., green–blue, red–green, gold–rose red).
Advantages:
- Easily verified by the naked eye
- Strong color-shifting effect resistant to scanning or copying
- Widely used in passports, banknotes, tax stamps, and high-security IDs
2. Fluorescent Ink (Ultraviolet/Infrared Fluorescent Ink)
Ultraviolet/Infrared fluorescent inks remain invisible or nearly invisible under normal lighting conditions.
When illuminated with Ultraviolet (UV) light or Infrared (IR) light, they reveal bright and easy-to-verify fluorescent images or text.
For Ultraviolet detection, two wavelengths are commonly used:
- 365 nm long-wave UV light
- 254 nm short-wave UV light
For Infrared detection, the fluorescent effect is activated using 980 nm IR illumination, which is invisible to the human eye.
Applications:
- Identity documents
- Brand protection labels
- Tax stamps and certificates
- Premium packaging
Benefits:
- Provides a covert security feature that is difficult to replicate.
- Enables fast verification with UV (365 nm / 254 nm) or IR (980 nm) detection tools
- Suitable for mid- to high-security applications
3. Thermochromic Ink (Temperature-Sensitive Ink)
Thermochromic inks change color when exposed to heat and are available in two types:
- Reversible: Color returns after cooling
- Irreversible: Permanent color change after heating
Common uses:
- Event tickets
- Transport passes
- Promotional and interactive labels
- Tamper-evident indicators
4. Magnetic Ink (MICR / Magnetic Ink)
Magnetic inks contain magnetizable particles that create a unique magnetic signal detectable by specialized readers. This makes them essential in secure document verification and automated processing.
Applications:
- MICR printing on checks and financial documents
- Machine-readable identity documents
- Track-and-trace systems
At Suzhou Image Technology, we enhance magnetic printing by integrating micro- and nano-optical structures with magnetic materials to produce magnetic holographic effects that combine visual impact with enhanced security.
Strengths and Limitations of Security Inks
Strengths
- Easy visual or tool-assisted verification
- Cost-effective for multi-layered security
- Compatible with various substrates and printing technologies
- Offers both overt and covert protection
Limitations
- Some ink types are increasingly available in the market
- Single-feature ink alone may not meet high-security requirements
- Performance depends on substrate and printing conditions
To achieve robust protection, global security printing adopts a layered approach, combining:
- Optical features (holograms, micro-nano structures)
- Machine-readable elements (magnetic signals, barcodes, RFID)
- Covert features (UV/IR fluorescence, microtext, invisible markers)
This strategy greatly improves authentication reliability and anti-counterfeiting strength.
Why Choose Suzhou Image Technology
With more than 20 years of expertise in optical security, Suzhou Image Technology integrates advanced optical structures, security inks, precision coating, and innovative material engineering into complete anti-counterfeiting solutions.
Our technologies are used for:
- Government IDs and secure cards
- Event credentials for conferences, parking, and sports events
- Vehicle windshield labels
- Brand protection optical labels
- High-security packaging and documents
By combining security inks with high-precision micro-nano optical features, we deliver authentication solutions that surpass traditional ink-based security and offer strong, scalable, and visually distinctive protection.
