Even amongst avant-garde watchmakers, De Bethune stands out for its substance – aesthetic and material innovation matched by technical ingenuity. At its core, the brand has reimagined the most fundamental aspects of mechanical timekeeping, from the barrel to the hairspring, while pushing the boundaries of traditional complications, be it the moon phase, tourbillon or chronograph.

But arguably its most distinctive innovation is an aesthetic one, which has come to define the brand no less – heat-blued titanium. The brand has used the alloy for more than 15 years across various parts of the watch, even making almost a whole watch out of it. But now De Bethune has a twist on the theme, resulting in the DB28 Yellow Tones in brilliant golden titanium.

Fiery yellow

Though the colour of the new DB28 is striking, it is by no means loud, as the amber shade of yellow isn’t the same as yellow gold and doesn’t pass off as such. In fact, it looks more like fresh brass than gold.

The colour was achieved through thermal oxidisation of the surface, essentially the same process as that used for blued titanium (and also the same for blued steel). The yellow surface, just like the blue, is the result of an oxide that forms on the surface of titanium when it is heated to a certain temperature. But amber yellow tone in this case was created by heating it at a lower temperature than used for blued titanium.

Titanium undergoes different stages of oxidation when heated, and yellow is one of the first colours that is achieved, followed by brown, purple, dark blue, light blue, green, yellow again, pink, magenta, blue, cyan, and yellow green. The higher the colour on the spectrum, the harder it is to achieve, especially with consistency across samples.

However, a higher temperature also induces the formation of a thicker oxide layer, which would mean that yellow is less resistant to scratches than blue.

The barrel bridge is finished with Cotes de Geneve, and the narrow triangular plate over it is mirror polished

Most of the front of the watch is yellow – the case middle, lugs, chapter ring, base plate, moon sphere, hands, delta-shaped barrel bridge, and the balance bridge.

Though the parts are made of different metals, the lugs are titanium while the balance bridge is steel, they are finished the same way: first mirror-polished, then cleaned, and finally heated individually by hand. As the components vary in shape, size and metal, the process had to be calibrated for each part.

Varied yellow

As the process is done by hand, even if the metal is the same, the colour will differ. So the result is an array of golden yellow tones that vary slightly from each other, lending the watch more depth and definition.

However, as mentioned above, the yellow finish is a surface treatment that does not change the metal below.  It’s therefore liable to scratches and chip, which reveals the natural colour of the metal below.

The only way to fix that is lengthy and expensive: remove the yellow layer, polish the part to remove the scratch, and then redo the heat treatment. The easier solution is to wear the watch very, very carefully.

Measuring 42.6mm wide and 9.3mm in height, the watch no doubt has an imposing presence on the wrist, but it is slim, elegant and sits flat on the wrist.

One of its most notable features is the ergonomics of the case, which fitted with sprung, hinged lugs that hug the wrist. The “floating” lugs were patented in 2006 and first introduced on DB26 perpetual calendar two years later.

Though the lugs on the new DB28 looks pretty much the same, they are actually the second generation design that’s been reshaped and resized. Now the lugs feature the brand’s signature “bullet” tips at the ends, a feature previously only found on De Bethune watches with fixed lugs.

More importantly, the new lugs are “intermediate” size, in contrast to the previous two options for lugs, long or short. The medium-sized lugs falls somewhere in between the two, giving the watch an effective length of 51-55mm depending on the position of the sprung lugs.

Fiery mechanics

One of the most impressive aspects of De Bethune watches is the concentration of in-house innovations in a single movement.

Despite being just a two-hander with a moon phase, the hand-wound cal. DB2115V4 boasts a total of five inventions, four of which – the titanium balance, triple “pare-chute” shock absorber, hairspring and spherical moon – are patented.

On the dial, the pair of mainspring barrels, offering a six-day power reserve, are visible on each side of the triangular barrel bridge. Six pallet jewels are incorporated inside each barrel, arranged like a three-pointed star on both the top and bottom faces, in order to minimise the friction of the mainspring against the barrel’s interior, thus optimising energy transfer and eliminating metal wear.

Located at six o’clock is De Bethune’s spherical moon composed of two half-spheres – one in palladium and the other in heat yellowed steel. It is accurate to one day in 122 years, the standard in watchmaking.

Further down the line is the escape wheel in silicon, which at less than a third the density of steel, operates with almost no friction and requires little energy. Though Swiss research institute Centre Suisse d’Electronique et Microtechnique (CSEM) holds the patent for silicon hairsprings, making them exclusive to its backers, namely Rolex, Patek Philippe, Swatch Group and Ulysse Nardin, silicon escape wheels and levers are being used by a variety of brands, from Jaeger-LeCoultre to Zenith to Laurent Ferrier.

Notably, De Bethune was the first brand to introduce a silicon balance wheel in 2008. It was fitted with platinum weights on its circumference and is now just one of nine balance wheels developed by the brand since 2004.

But the balance wheel in the DB28 is far more conventional. It’s made of blued titanium with white gold regulating weights on its periphery to achieve the perfect mass-inertia ratio.

The balance is held in place by a beautifully polished, yellow titanium bridge fitted with the brand’s triple pare-chute shock absorbers. It is essentially an extra pair of outboard springs at both ends of the bridge, in addition to the standard Incabloc shock protection for the balance staff, hence the triple pare-chute moniker.

Though made from conventional Nivarox alloy, the hairspring is distinguished by a unique architecture that was designed in-house. In contrast to the Breguet overcoil, which is high and vulnerable to shocks, the De Bethune hairspring is flat with a wider terminal curve, which reduces its height while ensuring concentric beating.

Turn the watch over and there is less to see, because the movement has been inverted in a way, to reveal the interesting mechanics on the front.

The watch pictured is a prototype and incorrectly marked “Steel Wheels” on the case back; the production version will read “Yellow Tones”

On the rear of the watch is only the power reserve, indicated by a golden pointer against a yellow titanium ring with a six-day scale. All of the power reserve mechanism is visible, including the large rack that drives the pointer.

Concluding thoughts

De Bethune watches are tremendously impressive both inside and out, and this one is no different. Moreover, its seductive, striking shade of yellow, while not as unique in watchmaking as blue, makes it one of the most unique De Bethune watches.

Key facts and price

De Bethune DB28 Yellow Tones
Ref. DB28YT

Diameter: 42.6mm
Height: 9.3mm
Material: Polished, yellow titanium
Water resistance: 30m

Movement: DB2115V4
Frequency: 28,800vph, or 4Hz
Winding: Hand-wound
Power reserve: 6 days

Strap: Alligator with pin buckle in yellow titanium
Price: 95,000 Swiss francs

For more information, visit Debethune.ch.

Correction October 31, 2019: A yellow oxide layer is achieved by heating titanium at a lower temperature than blue, and not higher as stated in an earlier version of the article.

Addition November 1, 2019: Included note that the watch pictured is a prototype with an incorrectly labelled case back.

Long the record holder for the most valuable watch at the biennial Only Watch charity auction, Patek Philippe has probably outdone itself this year. For Only Watch 2019, it’s put together a unique version of the most complicated wristwatch it’s ever made, the Grandmaster Chime ‘Only Watch’ ref. 6300A-010 in stainless steel.

Now in its 14th year, Only Watch is an auction of one-off timepieces donated by brands, with proceeds going to support medical research. Patek Philippe has claimed the title of the top lot in nearly all Only Watch auctions, including the most recent in 2017 that saw a Patek Philippe ref. 5208T in titanium sell for 6.2 Swiss francs. And in the auction before that, in 2015, the Patek Philippe ref. 5016A in steel sold for 7.3m Swiss francs.

But the steel Grandmaster Chime for Only Watch this year will probably exceed those results, albeit by a margin that’s hard to predict.

The buyer of “The Only One” will be the special one

By most metrics it’s the ultimate watch – not only is it the most complicated wristwatch ever made by Patek Philippe, it is also the most expensive timepiece in the current Patek Philippe catalogue. And then there’s the style of the watch, which is catered exactly to current tastes.

In fact, the elements of the watch are so perfectly suited to today’s fads in watch collecting that it might be a clever and discreet in-joke – a bit of humour from the serious Geneva watchmaker.

The size and complexity of the Grandmaster Chime mean it’s not really a beautiful watch, but it is impressive and appealing in a particularly kind of way. Importantly, this version is the best looking of the lot.

But before we continue, here’s a clip of the grande and petite sonnerie in action:

Grand in size and scope

Originally introduced in 2014 for the brand’s 175th anniversary in fully engraved, utterly baroque style as the ref. 5175 – limited to just six watches – the Grandmaster Chime was then streamlined slightly and entered the catalogue as the ref. 6300G, first with a black dial, and now in blue.

The power reserve indicator for the grande sonnerie – it’ll chime the time in passing for 30 hours in grand strike mode

The mode indicator for the striking mechanism: “S” for silent, “G” for grande sonnerie, and “P” for petite sonnerie

The sub-dial at 12 o’clock is the alarm time-setting display with the bell-shaped cut-out indicating if the alarm is on or off

The only calendar display on the front is the date

The power reserve indicator for the movement, which is 72 hours on full wind

It’s powered by the 300 GS AL 36-750 QIS FUS IRM movement, made up of an incredible 1366 parts and boasting 20 complications. The more important complications are the grande and petite sonnerie, instantaneous perpetual calendar, and chiming alarm.

But the more inventive complication is the date repeater that chimes out the date via the minute repeating mechanism. It strikes the date with a double chimes for each ten-day segment and a high chime for single days, so the 31st of a month will be sounded with three double chimes and one high chime.

The reverse face with the full calendar display

Unfortunately, none of that mechanical ingenuity is visible as the watch is double faced, with most of the functions being visible on the front, except for the perpetual calendar display that’s on the back.

A clever set of spring-loaded, swivelling lugs allowing the watch head to be rotated so it can be worn with either face showing.

The lugs can be pulled out, rotated and then released back into the case to switch watch faces

An image of the movement out of the case. Photo – Patek Philippe

All those complications, however, mean that the case is replete with pushers, buttons and slides to control all of the functions. Fortunately, most of them are helpfully labelled.

The button to active the date repeater, and also the correctors for the moon phase, marked “Lune”, and calendar, labelled “Quantieme”

Correctors for the year display – “Millesime” – and the months, marked “Mois”

“Jours” is French for “days”

And it also means the watch is huge. In fact, the movement alone is already 37mm in diameter, making it the same size as the vintage ref. 2499 perpetual calendar chronograph.

Dressed by hand

So it’s no surprise that the Grandmaster Chime is 47.7mm in diameter and 16.07mm high. It’s enormous. Because of that, the steel case makes practical sense, making the watch significantly lighter than the standard production gold model.

At the same time, the steel case seems to up the volume of the chimes slightly. Despite the size of the watch, the chimes are loud and clear – in fact, I could hear them with the watch in a display case about 2m away – although not as melodious as those on the smaller Patek Philippe repeating watches.

While the case may be large, it is finely executed, with all of its decoration having been done by hand. That includes the delicate clous de Paris, or hobnail, guilloche on the case, as well as all of the markings on the many buttons and pushers.

A Calatrava cross hand engraved on the crown

Like the case, the front dial is decorated with a hobnail guilloche engraved by a hand-operated rose engine.

Pink, Breguet and gilt

Steel is, of course, a fashionable metal in high-end watchmaking. That’s especially in vintage watches, but has also migrated to modern timepieces, so one-off or limited editions are now often done in steel.

That’s because, broadly speaking, complicated vintage watches with steel cases are rare, often making them more valuable than the equivalents in precious metal cases. The most expensive Patek Philippe wristwatch ever sold at auction remains the ref. 1518 in steel that sold for US$11m in 2016.

Another trendy feature in watch collecting now is a “salmon”, or pink, or copper, dial. All things being equal, a vintage watch with a pink dial will probably sell for more than the same in another colour. And watchmakers today know that. The presumed final edition of the Patek Philippe ref. 5270, for instance, was launched with a platinum case and “salmon” dial.

Besides “salmon”, another desirable dial finish is “gilt”, essentially a glossy, almost mirrored black finish with markings printed in shiny, metallic gold print. This too commands a premium in vintage watches.

Then there’s Breguet numerals, the italicised Arabic numbers named after Abraham-Louis Breguet (who probably popularised them but didn’t invent them). They evoke classical watchmaking, but are fairly uncommon in vintage wristwatches, making them desirable. So recent Patek Philippe watches with custom dials often feature Breguet numerals, including many made for Eric Clapton (including this ref. 5970/1G and this ref. 5004P).

The Grandmaster Chime in steel has a rose gold dial – made of an actual disc of solid gold – with applied, blackened gold Breguet numerals on the front. And on the back, the dial, also a solid gold disc, is what Patek Philippe describes as “black ebony”, a slightly glossy black finish with the hands and calendar display in rose gold – not quite a “gilt” dial but reminiscent of it. Everything’s there.

Concluding thoughts

That the Grandmaster Chime in steel will blow past its estimate of 3.0m Swiss francs is a given. How high it’ll go is the subject of relentless speculation.

My take is that it’ll probably finish around eight to ten million francs, given what is known about the number and spending power of the likely bidders, all of whom are well known to the industry. It’s a small circle, so the bidders and underbidders are often saleroom regulars, as was the case for the Patek Philippe grand complications at the last two instalments of Only Watch.

A major, outsized finish of 12m or 15m francs, or even more, is possible but only likely if an unexpected, deep-pocketed bidder buys the watch, or manages to push the winner further than expected.

Key facts and price

Patek Philippe Grandmaster Chime ‘Only Watch’
Ref. 6300A-010

Diameter: 47.7mm
Height: 16.07mm
Material: Stainless steel
Water resistance: None, but humidity and dust resistant

Movement: 300 GS AL 36-750 QIS FUS IRM
Functions: Lots
Frequency: 25,200bph (3.5Hz)
Winding: Manual wind
Power reserve: 72 hours

Strap: Alligator with steel folding clasp

The Patek Philippe Grandmaster Chime ‘Only Watch’ ref. 6300A-010 has an estimate of 2.5-3.0m Swiss francs. It’s lot 28 in Only Watch 2019 that takes place on November 9, 2019 at the Four Seasons in Geneva. For more, visit Onlywatch.com.

Update November 11, 2019: the Patek Philippe Grandmaster Chime ref. 6300A-010 sold for 31,000,000 Swiss francs, with no fees since it was a charity auction.