Latent Image Optical Authentication — Invisible in Normal Light, Revealed by an LED

GreenBworld latent image technology records an authentication mark as a microstructure formed directly on the film surface by nanoimprint lithography (NIL). Under ordinary diffuse lighting the mark is invisible to the naked eye and appears only when a directional point light source — an LED lamp or a smartphone flash — is shone onto the film. Because the mark is a physical structure rather than printed artwork it cannot be reproduced by scanning or printing, and because no dedicated reader is required, authenticity can be verified with a smartphone anywhere in the supply chain.

How It Works

The authentication image is not printed with ink. It is recorded as a microstructure imprinted directly onto the film surface by nanoimprint lithography, engineered to reflect and scatter incident light in specific directions only.

Under diffuse illumination — indoor lighting or daylight arriving from many directions — the reflected light spreads evenly, so the contrast created by the microstructure never emerges and the film reads as an ordinary surface.

When a directional point source such as an LED lamp or a smartphone flash is applied, the difference in reflectance between structured and unstructured areas becomes pronounced and the pre-set latent image becomes visible.

Because the image exists as physical nano- and micro-scale geometry rather than as visual content, high-resolution scanning and printing cannot reproduce it. And since no dedicated reader is needed, distributors and end consumers can verify authenticity instantly with a smartphone.

Key Features

Verification by eye

a smartphone flash or LED lamp reveals the mark; no dedicated reader is required

Not reproducible

the mark is structural, so scanning and printing cannot replicate it

Design freedom

logos, text, numerals and patterns can all be implemented

Layered security

can be combined with QR codes, fluorescent inks and holograms

Volume production

roll-to-roll processing supports large-scale label and tag output

Digital pairing

can be combined with a smartphone-based verification app for hybrid authentication

Applications

Field	Examples
Brand protection	Authenticity labels and tamper seals for cosmetics, spirits, luxury goods and pharmaceuticals
Industrial parts	Genuine-part tags for automotive and electronics, supply chain traceability
Identity documents	Employee badges, membership cards, certificates and warranties
Finance and ticketing	Gift certificates, admission tickets, vouchers
Packaging	Decorative surface finish that doubles as a security element

FAQ

How does this differ from a hologram?

A hologram creates a rainbow-colored interference image with a diffraction grating. Rather than diffraction, latent image technology uses the property of microstructures formed on the film surface to reflect and scatter incident light only in a specific direction.

Under diffused light coming from various directions, such as indoor lighting, the surface appears ordinary, but when illuminated with a directional point light source such as an LED light or a smartphone flash, the contrast between the area where the fine structure is formed and the area where the microstructure is not formed becomes clear, and a pre-designed logo or text appears.

Can it carry our own logo?

Yes. Supply the logo as a vector file and it will be incorporated at the microimage master design stage.

What are the minimum quantity and lead time?

A master mould must be produced first, so initial volume and lead time are agreed case by case.