Unit packet

The smallest individual packaging of a tobacco product (one pack of cigarettes usually holds 20 individual sticks).


A material that absorbs energy at a longer wavelength outside the visible spectrum and emits in the visible spectrum. The materials that can achieve this effect are rare and therefore used for security marking. Up-conversion is an anti-Stokes type emission.

Ultraviolet (UV) curing

A photochemical process in which high-intensity ultraviolet light is used to instantly cure or ‘dry’ inks, coatings or adhesives.

Ultraviolet (UV) dull substrate

A first-level requirement of security paper, which needs to be made from virgin pulp which is free of optical brighteners (ie. which is UV-dull). This is because optical brighteners mask or interfere with UV fluorescent security print and fibres.

Ultraviolet (UV) light

The part of the electromagnetic spectrum between 100nm and 400nm, or between visible light and X-rays.