While our inks are relatively broadly excitable from 365-390 nm UVA wavelengths, our inks fluoresce most brightly under high flux 365nm light for best color rendition.
If your application is commercial or industrial, please consider a high flux 365nm flashlight XeLED-Ni1UV-R5-365. The difference is striking between this flashlight and keychains and other flashlights using typical 5mm LEDs.
Having a nail-varninsh thickness, the IF2 inks for non-porus surfaces work really effectively on glass, metal, ceramics, and hard plastics. In fact on glass, glass cleaners can be used over and over and the UV markings made with the IF2 inks will remain.