In 1910, the Radium was used widely in military watches and instruments. As the luminescent material, the Radium has its advantages – radioactivity. Although the amount of radium in the watch is small and covered by glass,it still had risks if exposing a long time.
In 1949, the Radium was limited in civil market. The Tritium took its place which was much safer. As the luminescent material, the hour markers coated with Tritium will be faded after more than a decade. From the picture you will see the change of Oystersteel cases copy Rolex watches.
In 1993, a brand new material appeared – Luminova. Because the material is not radioactive, it is not self-luminous. On the other hand, it has excellent chemical stability and is not easy to be with aging phenomenon in the service life. On the picture, the perfect fake Omega Speedmaster is just coated with the Luminova.
In 2000, the Super-LumiNova was launched and it is the main luminescent material that majority of watch brands use.