What holograms are — and why they work as security features
A hologram is a photographic record of a light interference pattern that, when illuminated, reconstructs a three-dimensional image. Security holograms used on passports, banknotes, and brand protection labels are not true 3D holograms in the optical physics sense — they are Diffractive Optically Variable Image Devices (DOVIDs), also called kinegrams, that use diffraction gratings embossed at sub-micron scale onto a metallic or transparent film to produce optically variable effects.
The anti-counterfeiting value of a security hologram is manufacturing cost and complexity. Producing an authentic-looking diffractive security hologram requires: electron-beam lithography (to create the master at nanometre scale), vacuum metallisation equipment (to apply the reflective aluminium layer), and precision embossing machines. The capital cost for this equipment is in the range of ₹50–100 crore. No commercial printer has this capability — and no commercial service bureau offers it.
How security holograms are manufactured
The hologram manufacturing sequence:
- Origination: The design is created using computer-generated holography (CGH) software and written onto a photoresist-coated glass plate using an electron-beam or laser writer at nanometre precision. This creates the holographic master.
- Electroforming: The photoresist master is electroplated with nickel to create a metal shim — a hard negative of the diffraction pattern.
- Embossing: The nickel shim is used to emboss the diffraction pattern into a thermoplastic film (typically polyester/PET) under heat and pressure, at very high speed on reel-to-reel machines.
- Metallisation: The embossed film is vacuum-metallised with aluminium — a layer typically 30–50nm thick, thin enough to be transparent to light but reflective enough to diffract it.
- Lacquering and laminating: A protective lacquer is applied, then the holographic film is laminated onto its carrier (paper, PET, or BOPP) with adhesive.
Types of holographic security products
Hot stamping holographic foil
The most common security hologram application in India — a reel of holographic foil applied to a document, label, or packaging by hot stamp foiling. The foil transfers cleanly under heat and pressure from a die. Used on: FMCG brand protection labels, certificates, examination mark sheets, product authentication hologram stickers. Available from: Holostik India (Noida), Holo-Pack India, UFLEX Holographics, Rainbow Holographics.
Pressure-sensitive holographic labels
Pre-cut self-adhesive holographic labels on release liner — peel-and-apply. Used for: pharmaceutical carton authentication, electronics brand protection, warranty seals, bottle cap seals. Many include void features — the label leaves a "VOID" or "OPENED" pattern on the substrate when peeled, indicating tampering. Available from multiple Indian converters who source holographic film and convert into labels.
Overlaminates for identity documents
Transparent or translucent holographic films laminated over the entire biographical data page of identity documents (driving licences, voter IDs, employee cards). The holographic overlaminate makes laser-engraved or printed data visible while adding a layer that is extremely difficult to remove without destroying the underlying document. Used on: Indian driving licences, Aadhaar cards, PAN cards, employee identity badges.
Continuous holographic background (rainbow foil)
Decorative holographic pattern applied across the full background of a label or certificate. Provides basic anti-counterfeiting — the iridescent rainbow effect is visually distinctive and not reproducible by inkjet or laser printing. Lower security than custom DOVIDs — widely available and less expensive. Used on: gift vouchers, gift wrapping, decorative labels, and as a background security element on certificates.
VOID security labels
VOID labels are pressure-sensitive labels engineered to leave a visible pattern ("VOID", "OPENED", "WARRANTY VOID") on the surface they were applied to, or on the label face itself, when peeled. The VOID mechanism uses one of two approaches:
- Destructive face stock: The label face stock is designed to split at a layer beneath the surface when peeled — part of the label remains on the substrate, revealing "VOID"
- Residue-leaving adhesive: The adhesive leaves a "VOID" pattern of adhesive residue on the substrate when peeled
- Ink transfer: A layer of "VOID" ink transfers from the label to the substrate when the label is applied and then peeled
VOID labels are widely used in India for pharmaceutical packaging (ensuring the carton seal is intact), electronics (warranty seals on smartphones, appliances), and document authentication (sealing certificates and mark sheets).
Tamper-evident seals for pharmaceuticals
Indian pharmaceutical packaging uses several tamper-evident sealing formats regulated under Schedule M of the Drugs and Cosmetics Act and CDSCO guidelines:
- Blister pack foil seals: Aluminium foil lidding on blister packs — once peeled or pushed through, the seal cannot be restored
- Induction seal (wad seal): Aluminium foil disc heat-bonded inside a plastic cap using electromagnetic induction — cannot be removed intact
- Breakaway caps: Plastic caps with a bridge that snaps when first opened — visual tamper evidence
- Holographic carton seals: Self-destructing holographic label sealing the carton flap — leaves "VOID" if removed
- Shrink bands: Heat-shrunk PVC or PETG band around cap and bottle shoulder — visual if cut or removed
India's hologram industry
India has a developed domestic hologram manufacturing industry, concentrated in Delhi-NCR (Noida, Greater Noida) and Mumbai. Major manufacturers include Holostik India Limited (one of Asia's largest hologram producers), UFLEX Limited's holographics division, Holo-Pack & Print India, and Madras Security Printers. These companies supply holographic foils, security labels, and overlaminates to FMCG, pharmaceutical, and government clients domestically and export globally.