Patinoida

Patinoida is a Finnish verb meaning to form a patina or to patinate, and, by extension, to become patinated. The term is used for metal surfaces as well as for other materials that develop a thin film through aging, oxidation, or chemical treatment. In metalworking, patinoida refers to the intentional creation of a colored, protective, or aesthetic surface layer on metals such as copper, bronze, brass, steel, or silver.

Patina is the thin, often translucent layer that results from oxidation, chemical reactions, or long exposure to air and moisture. Its color and texture can range from brown and black to green, blue, or purple, depending on the material and the treatment. Patinoida often aims to achieve a specific color or finish for decorative or protective purposes.

Common patination methods use chemical solutions such as liver of sulfur, copper acetate, ammonium sulfide, ferric nitrate, or acids; natural patination occurs through weathering. In practice, artists and restorers can control the outcome to produce verdigris on copper, brown or black patinas on brass, or blue-green tones on bronze. Patination can also alter texture, not only color.

Patination is widely used in sculpture, jewelry, architectural decoration, and conservation. It can protect metal surfaces by slowing corrosion but can also affect value or authenticity; some patinas are left untouched for historical reasons, while others are renewed. See also verdigris, tarnish, oxidation, and patina.