[Senior Patek Moderator]
A little more info now from Patek on the amazing table clock Ref. 25014M-001, "Tokyo as the Crow Flies," a unique piece in cloisonné enamel!
From Patek's official description:
This unique piece notable for its original, exclusive design, is adorned with a stylized plan of central Tokyo, formerly Edo, in Grand Feu cloisonné enamel -- its streets, parks and lakes spilling over from the dial onto the convex side panels in silver.
All the areas to be enameled were first decorated with a guilloche "barleycorn" pattern, destined to shine through layers of translucent enamel. The enameller then laid down the "cloisons" (or partitions), using about 12.4 m of gold wire (~24 g) measuring 0.20 x 0.60 mm in cross-section, cut into tiny segments and shaped by hand.
To create his rich color scheme, he worked with a palette of opaque and translucent enamels in 16 shades. Each enameled element required from 10 to 12 firings at temperatures ranging from 800°C to 840°C. The dial is adorned with rhodium-plated trapeze-style hands. The four lozenge-shaped appliques set on the bezel mark both the quarter-hours and the points of the compass. This piece is powered by the caliber 17’’’ PEND TABLE mechanical movement rewound by an electric motor.