UVmerkning

UVmerking, or ultraviolet marking, is the application of ultraviolet-reactive substances to objects so that marks are invisible under normal light but become visible under ultraviolet light. It is used for covert identification, authentication, and tracking, often as a security feature or inventory control.

Most UV marks rely on fluorescent or phosphorescent materials. Fluorescent inks glow briefly when exposed to UV light, while phosphorescent pigments continue to emit after the light is removed. Common formats include inks, dyes, microdots, threads, or labels embedded in coatings and packaging. Detection requires a UV lamp or scanner, typically in the UVA range (approximately 315–400 nm).

Applications span currency and official documents, luxury goods, packaging, pharmaceuticals, art and archival items, and supply-chain tagging. UV marks provide quick, non-destructive verification and can be paired with other security features to deter counterfeiting and improve traceability.

Advantages include being covert, inexpensive, and fast to apply, with minimal impact on the visible appearance. Limitations include potential visibility under UV inspection, fading under bright sunlight, and variability in detection equipment. Skilled counterfeiters may attempt to imitate UV features, and some inks raise regulatory or safety considerations.

Where UV marking affects food contact, cosmetics, or children's products, regulatory compliance, migration testing, and material safety data may apply to the inks and substrates used.

See also: UV fluorescence, security ink, watermarking, microdots.