What Is Dual-Band UV Fluorescent Ink?
Dual-band UV fluorescent ink is an anti-counterfeiting ink that combines two UV-excited fluorescent materials in a single formulation. Under long-wave 365nm and short-wave 254nm UV light, it emits two different fluorescent colors respectively, creating a unique “one ink, two colors, wavelength-switching” security feature.
Compared with ordinary single-band UV fluorescent ink, dual-band ink shows only one color under a single light source. The color change only appears when switching between wavelengths using a professional dual-wavelength inspection lamp. This optical color-shifting behavior cannot be reproduced by the naked eye or ordinary copying equipment, making it one of the most widely used covert security technologies in high-end anti-counterfeiting packaging, documents and banknotes.
How It Works: 365nm and 254nm Dual-Wavelength Excitation
The principle of dual-band UV ink is straightforward: the formulation contains two fluorescent pigments — one sensitive to long-wave UV (365nm) and one sensitive to short-wave UV (254nm). During inspection, the two wavelengths are applied in sequence:
- 365nm long-wave irradiation: excites the first fluorescent material to emit its preset color (e.g. green or red);
- 254nm short-wave irradiation: excites the second fluorescent material to emit another color (e.g. red or green);
- When the UV lamp is switched off, both fluorescences disappear and the ink returns to a colorless or slightly transparent state.
The two fluorescent materials are uniformly dispersed through dedicated grinding and dispersion processes, without interfering with each other or migrating, ensuring clear, well-defined colors under both wavelengths.
Two Standard Color Combinations: Green-Under-365/Red-Under-254 and Red-Under-365/Green-Under-254
| Type | Under 365nm (long-wave) | Under 254nm (short-wave) | Visual Feature |
|---|---|---|---|
| Green under 365 / Red under 254 (Type A) | Green fluorescence | Red fluorescence | Green→Red switch, high contrast; ideal for banknotes and cigarette packaging |
| Red under 365 / Green under 254 (Type B) | Red fluorescence | Green fluorescence | Red→Green switch; common in high-end packaging and label security |
The two combinations can be used individually, or mixed within one design (e.g. Type A as background pattern and Type B for serial numbers) to form a complex two-color matrix security pattern that further increases imitation difficulty.
Key Technical Specifications
| Item | Specification |
|---|---|
| Long-wave excitation | 365nm (UVA) |
| Short-wave excitation | 254nm (UVC) |
| Standard color change | Green↔Red dual-color (custom combinations available) |
| Printing methods | Screen (solvent-based/UV), flexo, gravure, offset (by system) |
| Substrates | Paper, PVC, PET, PC, metal, glass, etc. |
| Certifications | ISO 9001, EN71.3, REACH |
Key Advantages of Dual-Band UV Ink
- Covert security: invisible or barely visible in natural light, without affecting design;
- Two colors at two wavelengths: one print carries two independent fluorescent messages — twice the information of single-band ink;
- High forgery resistance: color switching relies on specific wavelength excitation that ordinary copiers, scanners and cameras cannot reproduce;
- Rapid inspection: field authentication with a dual-wavelength lamp in seconds, no lab testing required;
- Stackable upgrade: combinable with IR-excitation ink, OVI color-shifting ink, thermochromic ink and other security technologies for a multi-layer security system.
Applications
- Documents & tickets: passports, ID cards, banknotes, tickets, lottery tickets, securities;
- Tobacco & liquor packaging: cigarette cartons, liquor boxes, cap labels security marks and hidden codes;
- Brand protection: cosmetics, daily chemicals, health products packaging;
- Food & pharma: pharmaceutical packaging, food label traceability;
- Card products: bank cards, membership cards, scratch cards, game cards;
- Certificates: diplomas, qualification certificates, contract anti-tampering marks;
- Electronics & auto parts: genuine product marks for components;
- Textile & footwear: hang tags, wash labels, anti-counterfeit woven labels.
Dual-Band vs. Ordinary UV Ink
| Comparison | Ordinary single-band UV ink | Dual-band UV ink |
|---|---|---|
| Excitation wavelength | Single (mostly 365nm) | 365nm + 254nm dual wavelength |
| Fluorescent color | Single color | Two colors, switching by wavelength |
| Security level | Medium | High |
| Inspection | Single-band UV lamp | Dual-wavelength lamp (wavelength switch required) |
| Imitation difficulty | Easier to imitate | Dual-band formulation required; much harder to copy |
Customization & Samples
Shenjiaheng Ink supports customizing fluorescent color combinations, shade depth and printing adaptability for dual-band UV ink. If you have sample cards, we can match the colors accordingly. Samples are charged by weight with flexible minimum orders and fast delivery after confirmation. You are welcome to send sample cards or color requirements — we provide free color-matching advice and sample testing.
FAQ
1. Is dual-band UV fluorescent ink visible in natural light?
No, or only barely visible. Fluorescent materials are essentially colorless under natural light; they only develop color under UV irradiation, making this a typical covert security ink.
2. What equipment is needed for inspection?
A UV inspection lamp with both 365nm and 254nm wavelengths. First observe the color under 365nm, then switch to 254nm to see the second color — authentication is complete.
3. What is the difference between Type A and Type B?
The display order of the two colors under the two wavelengths is reversed: Type A (green under 365 / red under 254); Type B (red under 365 / green under 254). They can be used alone or combined into a two-color matrix security pattern.
4. Can other color combinations be customized?
Yes. In addition to the standard green/red combinations, we support customizing blue, yellow, orange and other fluorescent color pairs, subject to sample confirmation.
5. Which substrates can dual-band ink print on?
Paper, PVC, PET, PC, metal, glass and more. Different resin systems are used for different substrates to ensure good adhesion.
6. Which printing methods are supported?
Screen printing (solvent-based/UV), flexographic, gravure and offset — choose the appropriate system according to your printing equipment.
7. How can I get samples?
Contact us with your color requirements or send sample cards, and we will arrange color matching and samples. Samples are charged by weight; once the order is confirmed, delivery is within 1-2 days after payment.
About Shenjiaheng Ink
Shenzhen Shenjiaheng Ink Co., Ltd. was founded in 2002, dedicated to the R&D and production of anti-counterfeiting inks for nearly 25 years, with an annual output of nearly 1,000 tons. We hold ISO 9001, EN71.3 and REACH certifications and are a member of the Radiation Curing Branch. Our product line covers dual-band UV fluorescent ink, UV invisible ink, IR-excitation ink, OVI optically variable ink, thermochromic ink, photochromic ink, glow-in-the-dark ink and mirror ink — eight series widely used in tobacco packaging, liquor boxes, banknotes, cards and packaging security.
For dual-band UV ink samples or technical support, please contact:
Tel / WeChat: +86 13510998453 (Kevin Wang)
Website: www.sjhink.com
Email: sz_qhy@hotmail.com