Blancpain Villeret Ultraplate 38 mm: The Engineering Realities of Scaling an Ultra-Thin Case

Blancpain announced in June 2026 a 38 mm version of the Villeret Ultraplate, adding it alongside the existing 40 mm reference. The movement inside both cases is the same: manufacture calibre 1150, an automatic with a 100-hour power reserve and an open-worked oscillating weight finished in yellow gold on steel models and red gold on red gold models. That last detail matters more than it might appear. Fitting an identical movement into a case 2 mm smaller in diameter is not a straightforward rescaling exercise. It is a set of compounding tolerance problems, and the Villeret Ultraplate’s particular construction makes each one harder to resolve.

What a 2 mm Reduction Actually Demands

The Villeret case is defined by its double-stepped bezel—a profile that consumes radial space in two distinct stages before it reaches the dial edge. At 40 mm, that geometry has room to breathe. At 38 mm, the wall sections between the outermost bezel step and the movement seat become genuinely thin. The machinist’s problem is that each step must still read as a discrete, flat surface when viewed from above, and each transition edge must hold a hand-bevelled finish. Compress the diameter and you compress the width of those surfaces. Narrower surfaces are harder to bevel consistently by hand because the tool has less material to register against, and any deviation in the bevel angle becomes proportionally more visible on a smaller face.

The case back presents a related constraint. The sapphire exhibition back must seal reliably while the overall case height stays consistent with the ultra-thin movement profile. Calibre 1150’s architecture sets the floor: the movement’s height is fixed, and the case construction must accommodate it without adding unnecessary thickness above or below. Every gasket groove, every snap or screw-down feature on the case back, has to be engineered into whatever wall thickness the 38 mm diameter allows after the movement seat and the bezel geometry have taken their share.

Finishing at Reduced Scale

The Villeret Ultraplate’s finishing vocabulary is not decorative in the loose sense. It is structurally specific. The Roman numerals applied to the dial are solid 18-carat gold, satin-finished on their upper surfaces with polished bevels on the edges. At 38 mm, the dial diameter is smaller, so the numerals must be resized for visual balance—the source confirms this was done deliberately. Resizing solid gold applied numerals is not a matter of scaling a CAD file. Each numeral is a discrete machined and finished component. Smaller numerals mean narrower bevel edges, which again tightens the finishing tolerance. The polished bevel on a numeral edge that is already measured in fractions of a millimetre has almost no margin for inconsistency before it reads as a flat face rather than a true bevel.

The XII position carries the JB monogram for Jehan-Jacques Blancpain rather than the traditional numeral. That substitution, introduced across the Villeret collection last autumn and now extended to the 38 mm, is itself a finishing challenge: a monogram at this scale requires the same satin-and-polished-bevel treatment as the numerals, applied to letterforms with tighter internal radii and more complex geometry than a straight Roman stroke.

Dial Construction and the Salmon Reference

The 38 mm launch introduces a sunburst salmon dial as a first for the Villeret Ultraplate collection. A sunburst finish—radial brushing from the dial centre outward—requires a consistent surface speed across the entire dial face to produce even grain. On a smaller dial, the geometry of that operation changes: the centre-to-edge distance is shorter, and maintaining uniform grain density from centre to periphery demands tighter control of the brushing process. The result, when executed correctly, is the shifting copper-to-gold appearance the reference is described as producing across different lighting conditions.

The 18-carat gold numerals on this reference are treated in a black finish, which contrasts against the salmon ground. Black finishing on gold components—whether PVD, DLC, or a chemical treatment—must adhere uniformly to the satin-finished upper surfaces without migrating onto the polished bevels. At the scale of an applied numeral on a 38 mm dial, that boundary is extremely narrow. The source does not specify the exact black finishing process used, so the method cannot be stated here, but the manufacturing discipline required to keep the treatment off the polished bevel edges is considerable regardless of technique.

Calibre 1150 and the Open-Worked Rotor

Calibre 1150 is visible through the sapphire case back, and the open-worked oscillating weight is a finishing commitment in itself. Open-working a rotor removes material in a pattern that must be machined cleanly and then finished on all exposed edges—not just the top surface. In a yellow gold rotor on a steel-cased watch, the contrast between the rotor material and the steel movement components is part of the visual logic. Every edge that faces the sapphire is a finished edge. At the movement dimensions dictated by a 38 mm case, the rotor’s geometry is constrained by the available diameter, and the open-worked sections must be sized so that the remaining bridges retain structural integrity under the rotational loads of an automatic winding system.

The 100-hour power reserve is a function of the mainspring and gear train design within calibre 1150, not a feature that changes with case size. But the case size does affect how the movement is accessed for regulation and service. A 38 mm case offers less clearance around the movement for the tools used during assembly and adjustment. That is a production reality that affects cycle time and, consequently, the consistency achievable across a production run.

The steel-and-yellow-gold reference—pairing a stainless steel case with solid 18-carat yellow gold numerals and a gold-toned opaline dial—extends the same finishing demands to a different material combination. Steel and gold require different surface preparation before finishing, and maintaining consistent bevel geometry across components in two different metals, which respond differently to cutting tools and polishing media, is a non-trivial manufacturing coordination problem. As the 38 mm format moves into broader production alongside the 40 mm, the consistency of that coordination across both sizes will be the real measure of the engineering work behind this case reduction.