Introducing Isotope Unveils the Altmann × Osaka Cloisonné Enamel Watch

Isotope Watches presents the Altmann × Isotope Osaka Cloisonné Enamel, a highly limited collaboration that transforms an unexpected source of urban design, Japanese manhole covers into a work of horological art. Limited to just five pieces, the watch features a hand-crafted grand feu cloisonné enamel dial, realized through an intensive process that spanned nearly a full year of development and production.

Isotope founder José Miranda has long been captivated by the artistry of Japanese manhole covers. Though part of everyday urban infrastructure, many of these covers display extraordinary graphic sophistication, cultural symbolism, and civic pride. The idea of translating these designs into watchmaking remained unresolved until Miranda discovered Manhole Covers of the World, a book by designer and illustrator Björn Altmann, which documents the typography, composition, and visual language of manhole covers with the same attention typically reserved for more traditional design forms. Altmann, an independent designer, illustrator, and typographer, brings over 17 years of experience in the creative industry.

The watch is housed in a polished 316L stainless steel case that balances elegance with durability, measuring 38mm in diameter and 10mm in thickness, extending to 44.5mm including the lugs. A domed sapphire crystal with anti-reflective coating protects the dial, while a screw-in sapphire exhibition case back reveals the movement. At 3 o’clock, a mirror-finished push-down crown engraved with the Lacrima logo provides a refined signature detail. Designed for both daily wear and active lifestyles, the case offers water resistance up to 100 meters, combining functionality with timeless aesthetics.

The dial draws inspiration from a municipal manhole cover in Osaka, Japan, depicting Osaka Castle at its center. Flowing water motifs and blooming cherry blossoms surround the castle, symbolizing the city’s connection to water and the cyclical renewal of the seasons. The Japanese characters 大阪市 (Ōsaka-shi) appear on the original cover, identifying it as an official municipal design rather than a decorative reinterpretation.

Each dial is built on a solid sterling silver base and executed using traditional grand feu cloisonné enamel techniques. Fine silver wires form the design’s structure, while multiple layers of vitreous enamel are applied and kiln-fired individually, with each color requiring its own application and firing stage. Due to the design’s complexity and the repeated kiln cycles, completing the five dials took nearly a year.

The production begins with precise CNC engraving of the silver base to define recessed sections, followed by meticulous hand-shaping and placement of fine silver wires to create the cloisonné cells. The enamel is carefully filled into each cell and fired at approximately 850°C. After each firing, shrinkage and surface irregularities necessitate repeated enamel application and kiln cycles—often up to ten times—until the dial achieves the correct depth and thickness. The final stage involves careful polishing to create a flawlessly smooth surface, with any imperfections corrected through additional firing.

Powering the watch is the Swiss-made Calibre I-7, a hand-wound mechanical movement based on a modified and regulated ETA Peseux 7001. Measuring 23.3mm in diameter, this ultra-thin caliber stands at just 2.5mm in height, allowing the watch to maintain a sleek and elegant profile. Decorated and hand-finished bridges reflect traditional haute horlogerie craftsmanship. The movement offers a 42-hour power reserve and operates at 21,600 vibrations per hour (3Hz), delivering precise performance alongside refined mechanical beauty.

The watch is paired with a quick-release white FKM CTS strap featuring a signed spring-loaded steel buckle, with an optional Mercury stainless steel bracelet. Each timepiece is accompanied by a signed copy of Manhole Covers of the World, the book that inspired the collaboration.

The Altmann × Isotope Osaka Cloisonné Enamel is limited to just five pieces: priced at GBP 3,600 (approximately 17,725 AED) with the white FKM CTS strap, and GBP 3,800 (approximately 18,700 AED) with both the strap and stainless steel bracelet.

For more information, visit Isotope official website.