Ultraviolet luminescent retroreflective sheeting

Ultraviolet luminescent retroreflective sheeting comprising a retroreflective region having retroreflective elements and an ultraviolet luminescent region which emits light under ultraviolet radiation;

• wherein the retroreflective region comprises
• an encapsulated lens retroreflective region comprising a support layer, a substantial monolayer of transparent microspheres partially embedded in one surface of the support layer, a light reflective layer coating on the portion of the transparent microspheres which are embedded in the one surface of the support layer, a transparent surface protective film facing in spaced relationship to the one surface of the support layer, and a series of bonding lines bonding the protective film to the one surface of the support layer to thereby form a plurality of sealed, small compartment cells, each of the sealed cells containing therein a part of the substantial monolayer of transparent microspheres, the non-embedded portions of which are exposed to the atmosphere within the sealed cell, or
• said retroreflective region comprises
• an encapsulated cube-corner retroreflective region comprising a support layer;
• a light-transmitting cover layer spaced apart from the support layer;
• a layer of cube-corner retroreflective elements disposed on one surface of the cover layer facing the support layer, a series of bonding lines bonding the surface layer to the layer of cube-corner retroreflective elements and forming a plurality of sealed, small compartment cells, each of the sealed cells containing therein cube-corner retroreflective elements which are exposed to the atmosphere within the sealed cell, and
• wherein the bonding lines comprise a fluorescent agent which emits light under ultraviolet radiation and a resin, wherein said bonding lines form at least a portion of the ultraviolet region, and,
• wherein when the ultraviolet luminescent region is illuminated with a fluorescent lamp which emits near-ultraviolet rays of main wavelength around 360 nm at a light-receiving intensity of 0.8 mW/cm.sup.2, the luminance is at least 10 cd/m.sup.2.