Feature: The Incredible Deadly Story Of Panerai

Panerai watches and luminescent paint go together like Tokyo and neon strip lights. It’s almost impossible to imagine these iconic timepieces without it. Indeed, the two models on which the company has built its reputation—namely the Radiomir and the Luminor—are named after the paint used on its signature sandwich dials.

Of course, easy-to-read dials were not a major draw for the average pocket watch-buyer in the late 19th century, back when Panerai was just a humble workshop and retailer in the heart of Florence. But Panerai didn’t sell luxury watches to the well-heeled residents of the Tuscan capital, they supplied them to the Italian railways and officers of the Italian Royal Navy.

Wearable Instruments

Making wearable instruments including depth gauges and marine compasses, however, meant that the markings and dials had to be highly legible, day or night—whether in soup-thick fog or the murky depths of the Mediterranean Sea.

So, as befitting a watchmaker in the ‘Birthplace of the Renaissance’, a city that’s home to the vivid works of Botticelli and Michelangelo, Panerai adorned its dials with its very own glowing paint, a mixture of zinc sulphate and radium bromide that it christened ‘Radiomir’.

Panerai's first luminescent paint was radium-based and highly dangerous.

This innovative substance, invented in 1910, proved a massive hit in the watch industry and beyond, especially during World War I, with Rolex, Breitling, Omega and many others employing thousands of women to meticulously hand-paint it on to watch dials. For greater accuracy, they would lick their brushes to moisten and shape the tip.

However by doing so, they were effectively signing their own death warrant. Unknown to anyone at the time, radium, a radioactive substance discovered a few decades earlier, had a potentially devastating effect on anyone coming into contact with it on a regular basis.

Elixir Of Death

A kind of poisonous version of calcium, radium gets incorporated into bones, causing necrosis and cancer. Incredibly, at the time, it was seen as an elixir used to cure anything from fatigue to arthritis due to its short-term energy-giving properties. It was injected into the throats of children to cure ear ailments. You could even buy it over the counter in the chemist in the form of a bottled liquid called Radithor.

American high-society figure and successful golfer, Eben Byers, drank a bottle of the stuff every day until his death aged 51. As the Wall Street Journal reported at the time, "The radium water worked fine until his jaw came off."

After the life-long work of scientist Marie Curie and her husband Pierre helped expose the truth about radium, its use in paint was banned. By the end of World War II, during which Panerai’s watches had been instrumental in helping the Italian Navy’s divers immobilise allied warships, it was about as welcome as anthrax.

The people at Panerai were left scratching their heads, faced with the possibility of losing one of the very features that gave the brand its distinct identity.

Time For Tritium

In 1949 they found an effective replacement in Luminor, a paint that was still radioactive, albeit much less so than the lethal Radiomir. The key ingredient this time was tritium, which could be made quite safe within a watch.

Exposure to small amounts of tritium, another phosphorous compound, is relatively harmless and can be expelled from the body. A patent was granted in 1950 and Panerai stuck with trusty Tritium until recently when it finally found something even more effective.

The name 'Radiomir' comes from the Italian words 'radio' (radium) and 'mira' (sight).

By the way, for those of you wearing a diving watch from the 1960s, whose dial almost inevitably has tritium lume, don’t panic. Your microwave or the Earth’s atmosphere probably emits more radioactivity. In fact, you can still buy watches new today with the stuff. Just don’t go licking the dial.

The Lume Of The Future

When Panerai emerged from semi-hibernation in the early nineties, having been given a welcome promotional boost by Sylvester Stallone and taken over by the Richemont Group, who invested heavily in the brand, it was time for another ‘lume’ overhaul.

Next in line was Japanese-developed alternative, LumiNova, produced in Switzerland under licence as Super-LumiNova.

In recent years Panerai has switched to using the perfectly safe Super-LumiNova.

This strontium aluminate–based substance is activated by absorbing UV and visible light before slowly radiating it out again, much like a battery. It’s also non-radioactive.

Providing up to ten times higher brightness than previous zinc sulphide–based materials, it’s been an industry game changer.

Panerai’s dials have always been one of the things that make it stand-out in an industry that sometimes lacks variation. Embellishing them with markers that stand out like mini light sabres, complementing that iconic font and sandwich layers has given the brand an even greater edge over its competitors.

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