The living finish of copper and brass: oxidation from skin oils, air, and time that shifts the surface toward browns, blues, and greens. Not a defect — on these metals, patina is the point.

Patina can develop naturally through carry and handling, can be accelerated with forced-patina solutions (liver of sulphur, vinegar, ammonia fumes), or can be polished back to bare metal whenever the owner chooses. The object is never finished — it is always in the process of becoming something.

High-contact edges and raised surfaces wear back to bright metal while recesses hold the darker tones, creating a natural relief effect over time. Collectors who track patina progress often photograph their objects at intervals.