Is Your Watch Radioactive? How That Luminous Dial Gets Its Glow

Originally published by Jack Forster on Hodinkee.

Luminous dials are a compromise. On the one hand, we would like to be able to tell the time in the dark without dropping a hundred large on a minute repeater. On the other hand we would also like our dials to age well, and inherent in the nature of many luminous materials, is that they will sooner or later dim to the point of uselessness. At that point, dials and hands are usually replaced if nocturnal legibility is desired – of course, do that to a vintage watch whose high value rests on originality of all parts, and you may have a watch you can read at night, but you will have destroyed its investment value.