How different watch brands have reimagined lume to transform the way we see time now

Back before lume was invented, the issue of reading time in the dark was likely addressed by repeating watches, minute repeaters, sonneries, and tact watches—Abraham Louis-Breguet made the first tact, or tactile, watch in 1799 to discreetly know time by touching the watch case rather than looking at the dial in polite society. Then came the discovery of radium, a radioactive chemical element, in 1898 by Marie and Pierre Curie. In 1902, William Joseph Hammer, an electrical engineer and laboratory assistant to inventor Thomas Alva Edison, worked on radium and invented radium-based luminous paint. He created a paint that would glow in the dark by mixing radium with zinc sulfide—luminescence had arrived.

Panerai was the first to adopt it and developed a radium-based luminous compound ‘Radiomir’, which was patented by the brand in 1916. Similarly, in the 1910s, Rolex and Omega quickly adopted radium for their watches till the mid-20th century, solving the nighttime visibility problem in one go. However, radium, being radioactive, had dangerous side effects—the story of the Radium Girls, female factory workers in the US in the early 20th century, who suffered radiation poisoning from painting radium dials, is a dark chapter in watchmaking. In the 50s and 60s, radium started getting phased out for relatively safer options, like tritium, and eventually, the completely safe LumiNova and Super-LumiNova®.

Today, the use of luminescence—both in terms of design and material—is lightyears ahead and far more evolved. An example is the limited-edition Oris Hölstein Edition 2025 (Ref. 01 400 7803 4781-Set) in its ProPilot collection. A first for the brand, its full-lume dial glows green and reveals an Oris Bear in the dark. Super-LumiNova®, composed of strontium aluminate, applied to the dial and the sapphire crystal ring on the caseback, glows after being charged by exposure to light.

Super-LumiNova®, the most common luminescence in watches today, was developed by Swiss technology company RC Tritec in collaboration with Nemoto & Co. Ltd., a Japanese company that originally invented the non-radioactive, strontium aluminate–based photoluminescent pigment LumiNova® in 1993. Super-LumiNova® is a high-tech ceramic compound that absorbs light energy from sunlight or artificial light and stores it temporarily to emit a glow in the dark. This cycle can be repeated infinite number of times without ever causing the material to age or diminishing its light storage capacity. A non-radioactive and non-toxic photoluminescent material, different brands use different grades of Super-LumiNova®. These include Standard, Grade A, and Grade X1, which provides the longest glow. Its luminescence also has a wide spectrum of glow, from off white to various shades of green and blue.

Some of the most recent admirable executions of Super-LumiNova® have been done by Horologer Ming, the Finnish watch brand Sarpaneva, and the British independent watch brand Studio UnderD0g on their watches. The Ming 20.01 Series 3, released last year, features a fused borosilicate dial with 600 voids arranged in a radially symmetric circular pattern. Each is hand-filled with a liquid Super-LumiNova® X1 by using syringes, which not just creates visual depth but also quite a presence on the wrist. Last year, the brand introduced 37.02 Minimalist, a timepiece that debuted the proprietary white emission luminous material—the Ming Polar White, developed at the brand’s Swiss manufacture in La Chaux-de-Fonds. With that, the brand once again proved how seriously it takes lume as a design element.
Every single Sarpeneva creation uses Super-LumiNova® creatively. In Sarpaneva x Moomin, the brand converted its dial into a canvas of storytelling by using different coloured Super-LumiNova®. The brand’s creation, like Nakki Blue Moon, features an exceptional dial showcasing 15 different Swiss Super-LumiNova® colours, hand-finished, hand-painted, on the art. Studio UnderD0g, on the other hand, uses a custom-made Super-LumiNova® for its 02SERIES collection, comprising Pink Lem0nade, Steffany Blue, Full Mo0n, and Midnight. The watches have a full-lume dial with seven layers of custom-made Super-LumiNova® pigment.

Recently, the introduction of Antarctic Diver Aquamar by Nivada Grenchen demonstrated that lume can also change on demand. The vintage-inspired dive watches feature Super-LumiNova® in two tones, a first for the brand, thanks to the rare sandwich dial construction. There is a faux patina lume for vintage watch lovers, while the white lume caters to the modern watch enthusiasts, which can be changed via the turn of a crown.

Another highlight in the world of lume is the innovation of LM3D, a proprietary photoluminescent composite crafted by Bell & Ross using epoxy quartz fibre, luminescent material, and resin. The material debuted in 2023, in the brand’s BR-X5 Green Lum 41 mm (Ref. BRX5R-LUM-TC/SRB), which featured a fully luminous case which glows bright green in the dark. Rolex also employs its own patented lume material called Chromalight. Developed by the brand in 2008, Chromalight is a combination of aluminium, strontium, dysprosium, and europium. The material emits a long-lasting blue glow and is standard on the brand’s Oyster Professional models. Upping the lume ante is IWC Schaffhausen’s Ceralume®, a luminescent ceramic, invented last year, that debuted in the brand’s Pilot’s Watch Chronograph 41, which featured lume on the case as well as on the strap. It is the world’s first fully luminous ceramic concept watch, thanks to the brand’s highly engineered Ceralume® technology, developed by the brand’s XPL division. Ceralume® is a luminous material composed of a homogeneous mixture of raw ceramic powders with high-grade Super-LumiNova® pigments, which can produce a glow for more than 24 hours.

The development of Ceralume® took several years. “The main challenges we faced were producing watch cases with maximum homogeneity and meeting our exacting quality standards. To achieve these goals, we engineered a ground-breaking new manufacturing process, tailored to the unique combination of ceramic powders and Super-LumiNova® pigments,” said Dr Lorenz Brunner, Department Manager, Research and Innovation, at IWC Schaffhausen. The white ceramic used for Ceralume® is made by mixing zirconium oxide with other metallic oxides. This powder is shaped into a ‘green body,’ which is roughly the size of the final watch case. It’s then heated at high temperatures in a kiln to harden it. For Ceralume®, the engineers developed a special ball milling process to evenly mix the materials, adjusting it specifically for the powders they used. Moreover, the engineers also fine-tuned the sintering and grinding stages to produce a luminous ceramic.

Though Super-LumiNova® remains the industry standard, just like IWC Schaffhausen, brands like Panerai, Seiko, and Rolex have also gone a step further and created their proprietary lume materials. Seiko’s proprietary material is called LumiBrite. It is also a strontium aluminate-based material, like Super-LumiNova, but it is brighter and provides longer-lasting luminescence. In 1993, Nemoto & Co. Ltd invented LumiNova pigments, and Seiko licensed and adapted it for its watches as LumiBrite. Models from Grand Seiko’s Evolution 9 and Sport collections also feature LumiBrite.

Panerai patented Luminor, a safer and more advanced lume material based on tritium compound, in 1949, but today primarily uses Super-LumiNova®. Another noticeable innovation by the brand is the creation of Panerai Submersible Elux LAB-ID (Ref. PAM01800), the first fully mechanical watch to use electroluminescence. Released last year, the watch can transform mechanical energy stored in four dedicated barrels into luminosity to light up 160 micro-LEDs on the hour markers, hands, and the bezel. The luminosity can be activated on demand by pressing the patented Elux pusher located on the left side of the case. The energy stored in the barrels is released in a microgenerator that converts it into electricity. The watch uses tiny micro-generators measuring just 8 mm by 2.3 mm, with custom coils, magnets, and a stator, moving with a high-speed rotor spinning 80 times per second to produce a 240 Hz electrical signal that powers the light system. This high-end technology is a result of eight years of research and development by the brand’s Laboratorio di Idee in Neuchâtel.

Apart from refining Super-LumiNova® or innovating proprietary compounds, some brands have taken an altogether different route and used alternative materials like Globolight®. It is a Super-LumiNova®-infused ceramic-based material, and interestingly, it can be shaped into any three-dimensional form and colour. Brands like H. Moser & Cie., Hautlence, and Christopher Ward use Globolight® as a lume material in some of their watches.

It is safe to say now that lume is far more than a practical tool. It is also a medium of expressing creativity, identity, and technological artistry in watchmaking. It looks like it will continue to shine bright in the years to come.

Images: Courtesy Brand