The most unique uses of lume in watchmaking

Jamie Weiss

Lume, the commonly accepted shorthand for the luminous phosphorescent glowing solution applied on watch dials and other watch elements, is typically quite a functional addition to a watch to help you tell the time in low-light conditions. But not always. Humans are just monkeys in shoes, and our ape brains love cool glowy things – we’re still drawn to fire after thousands of years – and it’s easy to get mesmerised by novel applications of lume. Full lume dials hold their own appeal, but I thought I’d assemble a list of some of the most unique uses of lume in watchmaking, from the whimsical to the technically impressive.

Spinnaker Fleuss Automatic seconde/seconde/ “Fifty Phantoms”

This playful collaboration between Hong Kong microbrand Spinnaker and French horological mischief-maker seconde/seconde/, released in time for Halloween 2023, epitomises seconde/second’s playful oeuvre and demonstrates that you don’t need to reinvent the wheel or spend big bucks to have fun with lume. A fairly faithful homage to early Blancpain Fifty Fathoms models, the “Fifty Phantoms” (as the name implies) has a dial adorned with 50 little ghosts filled with different colours of lume, flocking beneath typical lumed cathedral hands and filled indices. The three-dimensional nature of the dial makes it feel like the watch is being attacked by an onslaught of cheeky spirits. Very spooky. Price: US$445

Studio Underd0g 02 Series Field Midnight

While the other three models in the Studio Underd0g 02 Series Field range are full lume dials, meaning they’re outside the scope of this article (although you could make a strong case to include the Pink Lem0nade, as its pink-to-yellow gradient lume dial is an industry-first), the Midnight variant is worth discussing, and I think has been a bit slept on by the watch community. The 02 Series Field design features a unique take on a sandwich dial, where a base layer is topped with a transparent 1mm thick sapphire crystal dial, attached via two prominent screws, upon which the numerals and minute track are printed. In the Midnight variant’s case, rather than a full lume layer with un-lumed numerals on top, it has a conventional textured black dial with lume numerals hovering above. During the day, you get a 3D effect with the numerals casting shadows onto the dial below – and then at night, you get a different 3D effect as the glowing numerals appear to hover, turning the Field’s trademark dial effect on its head. This gives the Midnight a distinctly ethereal effect in the dark. Price: US$900, available exclusively in-store at Time+Tide Discovery Studios

Kollokium Projekt 01

The brainchild of GPHG-winning designer Barth Nussbaumer (who’s penned some of TAG Heuer’s Autavia range, along with Victorinox’s I.N.O.X and Petermann Bedat’s Reference 2941), the extremely sci-fi Kollokium Projekt 01 features a deceptively simple yet futuristic and charming use of lume. The dial of the Projekt 01 consists of 468 hand-applied, lume-tipped cylinders, positioned with differing diameters and heights to form discernable indices and create a wonderful textured depth. It reminds me of one of those metal pin art boards you see in museum gift shops – in a good way. A thick boxed crystal allows you to admire the matrix of cylinders from the side, too. Still a nascent brand, Kollokium has produced a number of limited runs of the Projekt 01 in different lume colours, with each release quickly selling out. Price: US$3,400

Bell & Ross BR-X5 Green Lum

Forget a full lume dial, what about a full lume case? That’s what the Bell & Ross BR-X5 Green Lum offers. This integrated sports watch features a multi-part case structure that alternates between grade 2 micro-blasted titanium and  a photoluminescent composite made from quartz fibres called LM3D, which is made exclusively for Bell & Ross. Matte in appearance, it’s a robust material that’s similar to some of the fibreglass composites used by high-end brands like Franck Muller and Richard Mille. LM3D is as strong as carbon fibre and 70% lighter than steel, meaning this BR-X5 is as tough as it is luminous. Price: US$13,300

Sarpaneva Näkki

Finnish watchmaker Stepan Sarpaneva is well-known for his creative use of lume, but I reckon the GPHG-nominated Näkki is his greatest work. Boasting an almost stained glass-looking dial with 650 cutouts coloured with 15 different shades of Super-LumiNova, the Näkki – named after the shapeshifting water spirit from Nordic folklore depicted on its dial – is, in two words, unbelievably artistic, almost resembling fine marquetry work. One of Sarpaneva’s most complex dials, it tells a story of a näkki being trapped by the moon’s light as it tries to escape back to its marshy lair, the monster shying away from Sarpaneva’s signature oversized moon face. It’s a beautifully Finnish watch that’s beautifully finished, too (sorry, couldn’t help myself). Price: starting at US$22,200

Audemars Piguet Royal Oak Concept Split-Seconds Chronograph, GMT, Large Date 43mm 26650FO.OO.D353CA.01

We’ve seen multiple watchmakers infuse carbon fibre with luminescent materials, including TAG Heuer with the original Aquaracer Solargraph and even the Heinrich Taucher in the microbrand space. However, Audemars Piguet’s Chroma Forged Technology (CFT), which makes its debut with this Royal Oak Concept, is easily the most interesting and complex execution of this technique yet. AP’s CFT is different as it colours the carbon fibres directly rather than the resin that binds them: in this watch, both blue and white colouring are incorporated into the carbon material, and the white glows blue in darkness once charged. The resulting effect is particularly mystical – it’s like looking into the heart of a galaxy. Price: US$206,800

Honourable mention: IWC Pilot’s Watch Chronograph 41 Ceralume Prototype

While it’s not been publically released yet – so far making its only public appearance on the wrist of Sir Lewis Hamilton at the 2024 Monaco Grand Prix – IWC’s Pilot’s Watch Chronograph 41 Ceralume prototype purports to be the world’s first fully luminous ceramic watch. This is significant as a luminous ceramic would be a more scratch-resistant and potentially even brighter material than, say, Bell & Ross’ LM3D mentioned earlier in this article. This material, which IWC is calling Ceralume, is created by homogeneously mixing ceramic powders with high-grade Super-LumiNova pigments. The resulting watch case reportedly glows with a bright blueish light for over 24 hours once fully ‘charged’. The concept watch also features a white luminescent dial and a white luminescent rubber strap that are both similarly enriched with Super-LumiNova. There’s been no word on when Ceralume will make its commercial debut, but this prototype Pilot’s Watch certainly ranks as one of the most unique uses of lume in a watch.