In watchmaking, there are codified levels of construction quality that distinguish variants of the same base caliber: it's not just about aesthetics, but about adjustment tolerances, control positions, and the depth of processing on internal components. I've seen identical Sellita movements come across the bench—same code, radically different care. That's where the hierarchy of grades becomes concrete.
The standard level represents current production without additional selection. The élaboré grade—a term consolidated in Swiss technical vocabulary—indicates a caliber tested in multiple positions, adjusted to tighter tolerances (typically ±5 s/day for Sellita in this bracket), with visible finishing like perlage on the plate and anglage on the bridges. Anglage is the polished beveling of bridge and plate edges: done by hand it takes hours per component, by machine it's more uniform but less deep. The difference shows under a loupe.
Top Grade, used by Sellita for certain SW300-1 and SW510 variants, pushes selection further: calibers are chosen from those already passing more severe tests, with personalized rotors and decorated finishes. Some third-party makers—I've verified on Farer examples—claim ±0 seconds per day on individual pieces, which is COSC chronometer performance without formal certification.
At the hierarchy's peak sit proprietary brands: the Poinçon de Genève mandates that the movement be built and assembled in the canton of Geneva according to finishing specifications defined by law, with inspection by a third party. The Patek Philippe Seal is instead an internal standard—more demanding than the Poinçon on some precision parameters in use—that the manufacture verifies autonomously. These are not directly comparable systems: one is institutional, the other is corporate.
The soignée grade, used by some makers like La Joux-Perret, sits in the same high bracket but without the Poinçon's legal weight. It indicates very high quality finishing attested internally. I have no independent documentation verifying its specific parameters outside manufacturer datasheets.
The practical hierarchy from the bench: standard → élaboré → top grade → third-party certifications (COSC, Poinçon) → proprietary manufacture seals. Each step involves real labor and selection costs, not just marketing.