High-visibility clothing is intended to clearly distinguish its wearer from his or her environment (and we’re not talking about that ruffled, powder blue prom tux). Your basic high-visibility garment most often includes two components: a bright background base and retroreflective accents. On some garments, especially gloves, you’ll find a third component—a performance material offering enhanced protection (referred to as ANSI/ISEA 107-2010 in industry-speak).
Back in the 1500s, a peculiar, yet naturally occurring blue opalescence caught the eye of Nicolás Monardes, and a few hundred years later in 1852, George Gabriel Stokes noted the ability of fluorspar and uranium glass to shift UV light to a higher wavelength of blue light. We now know this phenomenon as fluorescence.