Composite material having fluorescent features

摘要

The security feature comprises a transparent or translucent substrate 11 and two fluorescent components which fluoresce UV light at different visible colours and a UV light absorber. The fluorescent components may be in the form of coatings 12, 13 (Figs 1 and 2) or incorporated 15 in the substrate (Fig 3). The UV light absorber may be in the substrate 11 or as a layer 14 (Fig 2).