A pencil, a blank sheet of paper, and above all the Jaeger‑LeCoultre philosophy are all designers need to draw the faces of watches destined to become legends. First comes the sketch. Their initial role is to outline the ideas, display a function, or visualize a new concept. They are interpreters of the Manufacture’s language of shapes. Always attentive to current tastes, but with one eye turned towards the future, they remain true to the Maison’s long traditions. It is precisely this fusion of eras – this alchemy between past, present, and future – that characterizes the design of a Jaeger‑LeCoultre watch.
After machining, the calibre components are all hand- decorated like works of art. In order to live up to the technical perfection and match it with aesthetic perfection, the many beds and countersinks milled inside the bridges and plates are decorated in the smallest recesses, even those which are to be covered by other components.
In another unit the last complex and delicate operation on the plates and bridges - the jewelling, or setting of rubies - takes place. In use since 1902, these rubies have four functions: positioning the gear trains on the plates and the bridges; reducing friction; prolonging the piece’s lifetime; and serving as oil reservoirs for lubrication.
Jaeger‑LeCoultre was one of the first manufactures to produce and assemble its own watch pallets, and remains one of the last still to do so today. It is work requiring meticulous detail and high precision. Twenty-two different operations are needed in order to produce, decorate, and assemble the pallets.
The artisans of the Jaeger‑LeCoultre Manufacture were the first to innovate this gem-setting technique, which recreates all of Nature's magic. For snow-setting, the artisan jeweler relies on his own creativity and inspiration to fashion each new design directly into the material, guided exclusively by the piece itself and the motif he has imagined for it. Not a single error can be made. The setter places the diamonds one by one, side by side, deftly arranging their different diameters to completely cover the precious metal. Thus, the gem-setter's work is revealed little by little, as the stones – huddled against one another – form a cohesive layer across the surface of the metal. Such creative liberty requires great skill and meticulousness. In addition to the complexity of the designs and the time required to complete them, the selection of the diamonds in itself demands much expertise, as the tiniest stones must seamlessly merge into the most daring designs.
This centuries-old art had disappeared for over a generation when one of the Manufacture’s watchmakers resolved to rediscover its secrets in 1994. Nonetheless, it took several years before the first pictorial works could once again adorn the Reverso, as enameling is quite simply where painting meets alchemy. One value sums up this art: patience. The three enamel miniaturists now working in the Manufacture have mastered all the traditional techniques: grand feu, champlevé, translucent, and cloisonné. Still driven by the same thirst for new discoveries, they have recently developed an exclusive process, which gives the subject extraordinary depth. Just slightly tilting a miniature under any source of light will reveal a range of color variations and open up completely unsuspected perspectives and nuances.
Skill, experience, and imagination guide the slightest gesture of the engraver to the nearest hundredth of a millimeter. To preserve the shape of the components, he wedges them into a wax bed and works on them one by one. He first outlines the areas to be engraved with a fine line. Then he begins the chiseling, using a broader stroke so as not to carve too deeply and risk piercing the metal of the part. The components are then entrusted to the hands of the watchmakers for final assembly. Once assembled, the movement has the appearance of a luxurious openwork embroidery of utmost delicacy, adorned with rubies and blued screws.
Firmly convinced that the quality of a work of art can be seen in its smallest details, Jaeger‑LeCoultre goes to enormous lengths to ensure the decoration of its movements. Delicately hand-worked, the circular-graining, beveling, cold drawing, buffing, smoothing, and polishing must be worthy of the most complex mechanisms. Jaeger‑LeCoultre also knows the secrets of each material, whether it be steel, nickel silver, titanium, or aluminum, decorating even the most high-tech among them in traditional style. Each component is an aesthetic statement: conceived, cut away, and decorated to create an outstanding whole that will do justice to the beauty of the complication.
The movement is the organ which brings the watch to life. In the workshop where it is assembled, virtuoso gestures and skills that go back in unbroken continuum for over 180 years, succeed in awakening the inert material, as each watchmaker gives it a piece of his soul. The beating of the movement will always bear the memory of the master craftsman who gave it life.
The burins, chisels, files, and hammers used today are little different from those possessed by the ancient Egyptians and the Trojans. These tools have stood the test of time. The burin is the direct descendant of the coarse scraper. The wooden handle of this bevel-cut steel chisel is rounded to fit perfectly in the palm of the hand, the pressure of which controls the depth of the blade’s cut into the material. To be able to chisel the tiniest details and produce work of the highest precision, the master engraver uses some twelve different burins, of all sizes. He sharpens them himself, first with the sandstone grinder, then with the emery grinder, and finally with oil stone. The quality of his work depends on the care he puts into this operation: creating areas of shade is only possible with an impeccably polished cutting surface. It takes years of practice to learn to write on gold, steel, or platinum with the burin. First the sketch is traced directly with a dry point on the back of the Reverso. The drawing is then perfected using the appropriate burin for the engraving style required. An old engraving manual declares: “Writing should flow freely from the hand: this is the only way to achieve beautiful characters.”
In this workshop, imperfections invisible to the naked eye are hunted down to guarantee the perfect shine the case deserves. So that it may fulfill its function, the workshop is bathed in a dim light in stark contrast to the white light focused on each work station. The polisher's role is vital for attaining the degree of perfection that Jaeger‑LeCoultre requires of all items defined as "mirror polished". The Atmos clock must meet the same standard of finishing and is also subjected to a range of treatments such as smoothing, diamond polishing, buffing, and varnishing.
Traditional gem-setting allows the craftsman to add a personal touch to the motif. He decides both the exact positioning and number of stones to be set, as well as the precise design of the motif for each creation that is entrusted to him. He begins by drilling the smallest holes, and then drills the larger ones. Working his material like a sculptor, he carves and carves again progressively. Through these cuts he gives shape to the grain that will grip the stones. At this stage, each stone is put into place and must be carefully adjusted to ensure a perfect fit. Finally, the hole is circular-grained, so that the stone can no longer escape from its setting.
Cutting then profiles the cogs, wheels and pinions using a milling cutter which removes unwanted material until the perfect profile is obtained. Jaeger‑LeCoultre’s exceptional quality is due to a series of processes developed and perfected over the firm’s long history. These include rolling the pinions and the balance-wheel staff in order to improve the working of the watch. It is a manual operation which demands great skill, exceptional dexterity and excellent eyesight. An extremely delicate task given the tiny dimensions and the minuscule space worked on.
The need for extreme precision here incites man to entrust the fruit of his work to the machine. Parts in different materials (platinum, gold, steel, titanium…) are first stamped, then turned, milled and rectified. Drilled, shaped by grinding and lapping, then prepared for finishing operations. The minutiae of deburring as well as the pre-mounting require such delicacy that extreme manual dexterity is key.
Very rare in watchmaking, a veritable alchemist’s workshop treats materials to give them the necessary longevity. LeCoultre masters the art of quenching, tempering and annealing – three heat treatments to prepare the components to face eternity. In this workshop, screws are heated to a very precise temperature to obtain the right blue.
The dials are flat, bevelled or domed disks, positioned on the mainplate with feet. The dial surface is covered with layers of varnish. The hour indications and the other functions such as date, power reserve etc., are applied using transfers. This technique is also used to make day/night and moon phase disks etc.
In order to make the surfaces inalterable, an electroplated coating, consisting of a fine layer of nickel between 0.8 and 1.2 microns thick, is applied by electrolysis to the steel or brass parts. In addition the brass parts receive a 0.2 to 0.3 micron layer of rhodium or 24-carat gold. Thus each part is protected from corrosion or mechanical wear, which ensures its longevity. Jaeger‑LeCoultre is one of the last Manufactures with a complete mastery of electroplating, able to plate in numerous other metals, such as silver, palladium, ruthenium and different sorts of gold.
The casing up must be done in silence in an absolutely clean environment. All outsiders are categorically forbidden to enter this sanctuary with its positive pressure atmosphere. The calibre is placed in the case; dial and hands are delicately fitted; tweezers and screwdrivers sit alongside the casing cushion where the case rests on. After this step, the watches will shut away the secrets of their fine workmanship forever. Once assembled, the watch goes through a large number of tests and checks that Jaeger‑LeCoultre imposes on its timepieces.
The balance-wheel section is divided into several units: profile turning, blanking, drilling and tapping, screwing, assembly and balancing, and lastly pinning up to the stud and laser colleting of the hairspring in a small laser section. Jaeger‑LeCoultre keeps complete control of all component manufacturing processes.
In the dim light, adjusting the escapement – called achevage – ensures the distribution of the balance wheel’s force. The operation is controlled by projection. It is extremely painstaking work because tuning the pallet to the escapement wheel and the balance demands very nimble fingers. In a brighter room, some operations such as placing the balance wheel and the balance-cock on the movement, levelling and centring the hairspring on the balance, allow the movements to start ticking. The success of these operations ensures the watch’s accuracy for generations to come.
The Calibre-Maker is a watchmaker specialized in assembling and adjusting movements, also known as Calibres. Once the drawings have been finalised and the manufacturing plans precisely defined, it is possible to proceed to building a run of prototypes, generally ten or so. They are subjected to testing which can last from four to twelve months. Only after these trials are completed can the movement go into production. The care required at each step of this phase demands a considerable investment in time. For more complicated models, final approval of prototypes can take up to two years.
Very high precision swages cut out, drill, rectify, deburr and bevel parts such as: pallets, washers, wheels or springs from strips of various materials. Around 6000 swages are stored in the Manufacture. Some of them are still used for restoring old watches. The most powerful presses are reserved for pressing the parts of the Atmos clocks.