IWC just revealed an experimental Pilot’s chronograph with a luminous ceramic case – on the wrist of Formula 1 champion Lewis Hamilton at the Monaco Grand Prix. Christened Ceralume, the material was developed XPL, the watchmaker’s experimental engineering department. According to IWC, the Ceralume concept watch was glowing a bright blue for more than 24 hours in dark chamber tests (although it didn’t state how the material was “charged” prior to the test).

According to IWC, the patent-pending material is created by blending ceramic powder with Super-Luminova, the luminous material produced by RC Tritec that absorbs light energy and then emits it. Being non-radioactive, Super-Luminova is widely used to illuminate watch dials, and also suited to a case material. Though IWC has not revealed specifics about future plans for the material, it did say Ceralume will “form the foundation of future developments and releases.”

Lewis Hamilton at the 2024 Formula 1 Monaco Grand Prix

Initial thoughts

Ever since the discovery of radium in 1898, luminous materials have become commonplace in watches, primarily to aid legibility. With legibility being less crucial today, luminous paint is increasingly used for purely aesthetic purposes.

Moreover, luminous ceramic is not actually new. Tudor, for instance, used luminous ceramic hour markers in the Black Bay Pro of 2022. IWC is the first to make an entire case from the material, albeit not one that is available commercially (yet).

The luminous Pilot’s chronograph, however, is cool. In fact, the concept watch is essentially a cooler version of the Top Gun Lake Tahoe in white ceramic, one of the brand’s bestsellers. It is certainly something I look forward to seeing in regular production, although IWC’s recent watches in experimental materials have been arguably too pricey.

Glow-in-the-dark ceramic

According to IWC, the development of Ceralume took several years. One of the primary obstacles in perfecting the material was achieving a “homogeneous mix of [ceramic powder and Super-Luminova pigments] despite their different particle sizes and avoiding particle accumulations.”

The right mix was obtained by utilising a “ball milling process” to machine the raw case before it is sintered (or baked) in a specialised oven. IWC also tweaked the sintering and grinding processes to suit the material.

With the material perfected,  XPL created the luminous concept watch. Based on the Pilot’s Watch Chronograph 41, it has a Ceralume case along with a luminous dial matched with a luminous rubber strap. Both the dial and strap are manufactured in conventional manner: the brass base of the dial was coated with Super-Luminova before the markings were printed, while Super-Luminova was added to the synthetic rubber as the strap was injected moulded.