true demonstration of the craftsmanship and expertise of La Fabrique du Temps Louis Vuitton, two new Tambour Moon Flying Tourbillon “Poinçon de Genève” complete the colour palette of this exceptionally transparent family of watches.

The new watches, crafted from single blocks of synthetic sapphire, come in fluorescent green or yellow cases. These transparent creations are true feats of technical and artistic know-how, the first of their kind in the history of watchmaking to bear the Geneva Seal. They herald a new era, revealing all the secrets of their skilfully openwork Manufacture movement driven by a flying tourbillon.

The Tambour Moon Flying Tourbillon “Poinçon de Genève”, the first watch collection with a sapphire case to bear Geneva Seal, has been expanded this year with two new timepieces graced with the expert craftsmanship of La Fabrique du Temps Louis Vuitton. There is great potential in using cases cut from a block of coloured synthetic sapphire.

This pure and precious mineral is obtained by heating aluminium oxide at temperatures of around 2000° Celsius. Ever since the early 20th century, when this manufacturing process was invented by French chemist Auguste Victor Louis Verneuil (1856-1913), the watch industry has been using it to produce rubies for mechanical movements.

By dint of progress in its development during the 1980s, the industry succeeded in producing the first sapphire crystals for sports watches and, a decade later, the first complete cases.

Virtually unalterable like pure gold or platinum, with a hardness only surpassed by diamonds, synthetic sapphire is one of those precious materials over which time has no control. La Fabrique du Temps Louis Vuitton immediately grasped its potential, using it to protect the LV90 calibre from external stresses. It provides an impenetrable barrier to all but the eye and ensures that the exceptional openwork movement, regulated by a flying tourbillon, will have a virtually unlimited life span, provided that it receives regular care.

The Manufacture’s engineers have been experts in its application ever since the launch of the Tambour Moon Flying Tourbillon “Poinçon de Genève” watches in clear, blue and pink sapphire. This year, these artists, a bit of alchemists, have found the right formulas and the purest metal oxides in secretly guarded proportions.

They have created two new exceptional pieces with daringly translucent shades, so intense that they give the impression of being fluorescent. The first features an electric yellow sapphire case and the second comes in warm green accents.

To obtain a case middle, a case-back and a bridge bearing the LV logo in a strictly identical colour for each watch, a cylinder, 50 mm in diameter and 150 mm long, had to be extracted from the centre of a block of mass-tinted sapphire from Japan weighing nearly 200 kg.

Each component is therefore cut from this sapphire crystal bar using diamond tools to obtain the pieces final dimensions. All the elements are then delicately polished to reveal their transparency and the richness of the two meticulously selected colours.

The entire synthetic sapphire case of each watch requires 420 hours of complex operations on digitally controlled machines working with diamond tools. The 10 mm thick monobloc part alone, comprising the case middle, the bezel and the glass, requires 100 hours of milling and 150 hours of polishing. The case back needs 50 hours of machining and 60 hours of hand and machine finishing to become fully transparent and ready for assembly. Finally, the transparent bridge bearing the LV logo takes 20 hours of cutting and 40 hours of manual finishing to let the light pass through flawlessly.

Constant and meticulous attention is given to every detail throughout the entire manufacturing process. The 12 letters forming Louis Vuitton are engraved on the outer side of the concave case middle of the Tambour Moon, which appeared in 2017.

Like the indexes on the bezel flange, whose design gives the timepiece a very open face, they are delicately lacquered in white for the green sapphire version, and black for the yellow sapphire model.

The two horns, in black PVD-treated titanium, are attached by screws. Finally, to protect the delicate movement from external stresses, this 42.5 mm case with a thickness of 9.9 mm is guaranteed water- resistant up to 30 metres. This is achieved via a transparent gasket positioned between the case middle and the screw-down case back.

This light-flooded case draws the eye of the observer across the almost spider-like architecture of the LV90 hand-wound mechanical movement, which has an 80-hour power reserve.

To highlight the contrasts and emphasise the meticulous finishing required to meet the criteria of the Geneva Seal, the bridges and plate are shaped by a series of matt black circles. These almost fractal designs, with their delicate twists and turns, encourage the eye to plunge straight into the flying tourbillon, whose finely openwork carriage features the famous Monogram Flower motif. Transcending the balance of forms through a hypnotic kinetic interplay, the structure of the calibre is itself sublimated by the case exceptional yellow or green hue.

Everything on this timepiece has been carefully considered, right down to the appearance of the hands, which are light and hollowed out, floating over the circles from which they seem to spring. Like the previous versions of the Tambour Moon Flying Tourbillon Sapphire, these two spectacularly light and transparent watches are, to date, the only models in the world to have a sapphire case and bear the Geneva Seal. Their sheer complexity means they are produced in very limited series every year.

A true guarantee of excellence, this certification was introduced by the Grand Council of the Canton of Geneva in 1886. It is considered the highest guarantee of origin, finish and precision in the industry. Since 2012, the certification means that, from the case to the movement, every watch component must have been made and finished by hand in the Canton of Geneva by experienced craftsmen, in accordance with the profession’s highest quality standards.

Once assembled, each timepiece undergoes a series of tests and checks to guarantee the quality of its workmanship, its water-resistance and the precision of its calibre. At the completion of these tests, only the pieces that have passed all of them are individually awarded the most prestigious of watchmaking distinctions. Thanks to this unique seal, these exceptional, customisable watches attain the status of a work of art and come with an individual certificate issued by the Geneva Seal Office.