From its birth in 19th-century pocket watches to the current arms race between top manufacturers, we trace the history of a fascinating corner of horology.
Piaget's Calibre P9 hand-wound movement - (Image by Piaget)
Turn a Piaget Calibre 9P-powered dress watch sideways, and you’ll notice a curious phenomenon — it almost disappears.
While reducing a watch’s component parts down to their thinnest possible form does little in the way of added functionality or complication, the ability to construct a working ultra-thin timepiece does demonstrate the watchmaker’s skill. The limits of physics and materials science; the competence of the assemblers; the imagination required to rethink time-tested movement layouts — all are tested to an extreme during the design of an ultra-thin watch. And there’s no denying the beauty inherent in such a design.
But what sparked the modern horological arms race that continues to yield such fascinatingly slimmed-down pieces?
Actually, Swiss firms began experimenting with successively thinner designs as early as the 19th century. Take a look at the progression of pocket-watch construction over the several-hundred years leading up to the dawn of the 20th century, and you’ll notice the big slim-down. And frankly — who wouldn’t want a thinner pocket watch? Positioned within a pocket on one side of a gentleman’s waistcoat, a model that was too thick could be physically uncomfortable wear, while a thinner one was not only more elegant, but more pleasant to walk around with.
Cartier Art Deco-style 'couteau' pocket watch - (Image by Antiquorum)
The problem, of course, is that an average watch movement consists of stacks of componentry — the barrel, gear train, escapement, bridges, etc. In order to achieve true ultra-thinness, classic layouts needed to be rethought, while individual components needed to be slimmed down. Lose too much mass, and you risk the structural integrity of a particular component, not to mention the accuracy of the timepiece that it’s powering. In 1903, French watchmaker Edmond Jaeger challenged Swiss manufactures to design an ultra-thin pocket watch calibre. Jacques-David LeCoultre responded, designing the Calibre 145 in 1907. Measuring just 1.38mm thick, it became known as the Couteau (“knife”) calibre and powered numerous beautiful pocket watches, including models from Cartier.
Audemars Piguet Calibre 2003 hand-wound movement - (Image by Grail Watch Reference)
In the aftermath of the First World War, as timepieces migrated to the wrist, numerous top movement makers began designing progressively thinner ébauches for maisons such as Jaeger-LeCoultre, Audemars Piguet, Vacheron Constantin and Patek Philippe, some of whom also manufactured their own ultra-thin calibres. Audemars Piguet’s Calibre 9ML of 1938, for example, measured just 1.64mm, and would later influence the design of the manufacture’s Calibre 2003, a famed hand-wound movement from 1953. And it wasn’t just time-only designs that received the ultra-thin treatment: introduced in the early 1940s, Vacheron Constantin’s Ref. 4261 minute-repeating wristwatch was powered by a 13-ligne calibre that measured just 3.2mm thick, yielding a timepiece with a case height of just 5.25mm.
Piaget Calibre 12P automatic movement - (Image by Piaget)
By the 1950s and 1960s, however, top manufactures had truly taken up the ultra-thin cause, applying their design acumen not only to hand-wound designs, but also to automatic ones. In 1957, Piaget launched the hand-wound Calibre 9P, an impressively thin movement measuring just 2mm thick. However, in 1960, it followed this achievement with the Calibre 12P, an automatic movement that added only 0.3mm in thickness, for a total height of just 2.3mm. By integrating a micro-rotor into the mainplate’s plane rather than positioning it above the main componentry, it was able achieve a remarkable feat — namely, becoming (briefly) the world’s thinnest automatic watch movement. Likewise for Audemars Piguet, which introduced its own ultra-thin automatic, the 2.45mm Calibre 2120, in 1967. (The date-equipped version of this movement, the Calibre 2121, went on to power the legendary Royal Oak in 1972.)
In the 1970s, the Swiss horological industry went through a tumultuous period in which cheap and plentiful — not to mention highly accurate — quartz-powered movements threatened to destroy mechanical watchmaking. However, quartz also provided maisons with the unique opportunity to create extraordinarily thin movements, which Piaget took advantage of when it introduced the Calibre 7P in 1976. The world’s thinnest quartz movement at introduction, it measured just 3.1mm tall and was fitted to the solid-gold Piaget Polo in 1979.
Vacheron Constantin 'Ultra-Thin' Dress Watch
Many maisons, however, cut against the grain and brought their traditional savoir-faire to the fore by introducing ultra-thin mechanical dress watches with broad dials, narrow bezels, small crowns, and wafer-thin precious-metal cases. Powered by hand-wound movements such as Vacheron Constantin’s 1.64mm-tall Calibre 1003 — which the brand had introduced back in 1955 — and openworked versions of Audemars Piguet’s aforementioned Calibre 2003, these incredibly elegant pieces are still prized by collectors today.
By the 1990s, mechanical watchmaking had taken hold once again, and the Swiss watch industry was well on its way to a broader revival. Ultra-masculine, automatic watches from the likes of Panerai, IWC, and others saw case dimensions — both diameter and height — balloon, with little practical regard to comfort…or to the average human wrist circumference, for that matter. However, it was during this time that Piaget launched its Altiplano line — inspired by the aforementioned Calibres 9P and 12P, the collection would evolve to feature some of the most stunning ultra-thin watches in the world.
Bvlgari Octo Finissimo Ceramic 'Skeleton'
By the 2010s, a sea change was beginning in the horological sphere, and maisons were once again turning their focus to thinness — and, eventually, smaller, more classically inspired case diameters. In 2014 Bulgari launched its Octo Finissimo collection. By bringing record-breakingly thin tourbillon, minute repeater, automatic tourbillon, chronograph GMT, perpetual calendar, and other complications to the market, it proved that the ultra-thin watch need not be a strictly dressy affair made for pairing with black-tie formalwear.
RM UP-01 Ferrari - (Image by Richard Mille)
This also led to what might be termed the culmination of the thinness “arms race”: almost as soon as Bulgari announced the thinnest mechanical watch in the world in 2022 with its 1.8mm Octo Finissimo Ultra, Richard Mille snatched the crown with its 1.75mm RM UP-01 Ferrari. (No matter, however: Bulgari snatched it back when it debuted the Octo Finissimo Ultra COSC, which measures 1.70mm thick. And Konstantin Chaykin beat this watch with its 1.65 mm ThinKing prototype in 2024.)
The Piaget Altiplano Ultimate Concept comes in at just 2mm thick - (Image by Piaget)
Much of this horological magic was accomplished by changing the way that watchmakers think about the traditional layout of a mechanical movement: Piaget’s Altiplano Ultimate Concept, for example, turns the caseback itself into the movement’s mainplate, while other manufacturers utilize peripheral winding rotors, micro-rotors, and other components/techniques to shave off tenths of millimeters. All of this, of course, comes at a cost: eliminate enough material, and components run the risk of bending or breaking entirely, not only compromising accuracy, but potentially rendering the movement inoperable. This is a key reason why materials science has grown alongside ultra-thin watchmaking, offering watchmakers special alloys and substances that offer the best of both worlds with respect to strength, flexibility, and other essential qualities.
Today, it’s not only modern ultra-thin watches — which can run in the hundreds-of-thousands to millions of dollars — that are exciting collectors. Rather, vintage dress watches from the mid-20th century are also capturing mindshare, especially as tastes change from a tool-watch focus to a wider aperture that includes smaller, more formal models from the 1940s, ‘50s, ‘60s, and ‘70s. At Analog:Shift, we have long prized these beautiful pieces not only for their impressive thinness, but also for their simplicity of design — a combination that can’t help but yield a timeless sense of elegance.
Thin and Ultra-Thin Watches at Analog:Shift
Universal Genève 'White Shadow' ($1,950)
Universal Genève 'White Shadow' - IN THE SHOP
Introduced in the late 1960s, Universal Genève’s White Shadow utilized an ultra-thin automatic movement featuring a recessed micro-rotor in place of a traditional full-sized winding mass. This ingenious architecture allowed the manufacture to produce exceptionally slender self-winding watches — including this handsome 1970s example housed in a 35mm stainless steel case.
Hamilton Thin-O-Matic ($1,850)
Hamilton Thin-O-Matic - IN THE SHOP
Introduced in the early 1960s, Hamilton’s Thin-O-Matic collection combined American design sensibilities with Swiss automatic movement technology. During an era when manufacturers were competing to produce ever-thinner self-winding calibres, these elegant dress watches offered automatic convenience in remarkably slender cases. This stainless steel example measures a restrained 34mm in diameter.
Piaget 'French Altiplano' ($5,800)
Piaget 'French Altiplano' - IN THE SHOP
Few maisons are as closely associated with ultra-thin watchmaking as Piaget, whose groundbreaking hand-wound Calibre 9P debuted in 1957 at just 2mm thick. This elegant 1970s white gold dress watch embodies the same philosophy of mechanical miniaturization, pairing an ultra-thin, manually wound movement with a minimalist dial and slender case.
Hermès Slim D'Hermès GMT for HODINKEE ($19,500)
Hermès Slim D'Hermès GMT for HODINKEE - IN THE SHOP
Proof that complicated watches needn't be thick, the Slim d'Hermès GMT combines the ultra-thin, micro-rotor-equipped H1950 automatic movement with an Agenhor-developed second-time-zone module. Produced in a limited edition of just 24 pieces for HODINKEE, this elegant travel watch pairs sophisticated contemporary engineering with Hermès' distinctive approach to typography and design.
Patek Philippe Ellipse ($105,000)
Patek Philippe Ellipse - IN THE SHOP
Introduced in 1968, Patek Philippe's Golden Ellipse has long embodied the marriage of elegant design and ultra-thin watchmaking. This contemporary Reference 5738/1R-001 houses the celebrated Calibre 240, an automatic movement measuring just 2.53mm thick thanks to its recessed micro-rotor. Its slender rose gold case and matching bracelet complete the sophisticated package.
Audemars Piguet Huitième Chronograph ($22,750)
Audemars Piguet Huitième Chronograph - IN THE SHOP
A fascinating example of ultra-thin movement technology applied to complicated watchmaking, this 1990s Huitième Chronograph pairs a Jaeger-LeCoultre-derived, ultra-thin automatic base movement with a Dubois Dépraz chronograph module. The modular construction allowed Audemars Piguet to incorporate chronograph functionality atop a remarkably slender caliber, housed here in an unusual tantalum and pink gold case.
Zenith Ladies Elite Ultra Thin Moonphase ($5,150)
Zenith Ladies Elite Ultra Thin Moonphase - IN THE SHOP
Demonstrating that ultra-thin watchmaking needn’t come at the expense of mechanical complexity, Zenith’s Elite Ultra Thin Moonphase houses the automatic Calibre 692, measuring just 3.97mm thick. Despite incorporating a moonphase display and subsidiary seconds, the movement fits within an elegant 33mm case measuring approximately 8.65mm thick.
