SJH UV fluorescent yellow security ink test: bright yellow fluorescence under UV light, prints invisible and glows under UV - for cigarette packs, tickets and cards.
A full written description of the demonstration, so the content is readable without playing the video.
This video demonstrates the fluorescent yellow effect of SJH UV fluorescent ink: colourless transparent printing under visible light, bright yellow fluorescence under a UV lamp.
The video first shows the print in daylight, where the ink layer is colourless and transparent and the pattern does not appear - the print looks essentially unprinted. Fluorescent yellow is one of the most widely used covert security colours: it has high fluorescence efficiency under UV excitation and good visual recognition, while not disturbing the packaging colour scheme.
The camera switches to a UV lamp and the ink layer shows bright yellow fluorescence. Fluorescent ink performance is judged on three things: excitation brightness, purity of the fluorescent hue, and edge sharpness of the pattern. Insufficient efficiency shows up as a dull, dim glow, usually related to pigment concentration, film thickness and substrate absorption.
The video helps explain substrate compatibility. Fluorescent effects perform best on light, high-whiteness substrates; dark substrates absorb part of the fluorescence and reduce brightness. Printing over a coloured area weakens it similarly, so in practice the fluorescent pattern is placed in blank or light areas.
| Covertness | Colourless and transparent in visible light, leaves the design unchanged |
|---|---|
| Quality check | Excitation brightness, hue purity, pattern edge sharpness |
| Substrate | Best on light high-whiteness stock; dark substrates reduce brightness |
| Typical use | Cigarette packs, tickets, cards, labels and other covert security needs |
UV fluorescent ink is the lowest-barrier and most widely used covert security option: cost-effective, a mature printing process, and verifiable with a single handheld UV lamp. Its performance depends heavily on the substrate, so specify the stock and the background colour of the printed area - the same ink can look noticeably different on white card versus a dark area. Judge from a proof on your actual substrate.
Selection, detection, printing and ordering — answered.