Ormolu is the gilding technique of applying finely ground, high-carat gold–mercury amalgam to an object of bronze, and objects finished in this way. The mercury is driven off in a kiln, leaving behind a gold coating. The French refer to this technique as "bronze doré"; in English, it is known as "gilt bronze". Around 1830, legislation in France outlawed the use of mercury for health reasons, though use continued to the 1900s.

Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal, wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was traditionally silver in the West, to make silver-gilt objects, but gilt-bronze is commonly used in China, and also called ormolu if it is Western. Methods of gilding include hand application and gluing, typically of gold leaf, chemical gilding, and electroplating, the last also called gold plating. Parcel-gilt objects are only gilded over part of their surfaces. This may mean that all of the inside, and none of the outside, of a chalice or similar vessel is gilded, or that patterns or images are made up by using a combination of gilt and ungilted areas.