Composite body, painted, and glazed bottle. Dated 16th century. From Iran. New York Metropolitan Museum of Art.

Herakles resting on a couch, black-figure side of a vase by the Andokides Painter, circa 520/510 BC. Munich: Staatliche Antikensammlungen

Glaze is a layer or coating used on pottery or ceramics. It may be called vitreous enamel or porcelain enamel. Powdered glass is fused onto ceramics by firing to between 750 and 850 °C (1,380 and 1,560 °F). The powder melts, flows, and then hardens to a smooth, lasting vitreous coating on metal, or on glass or ceramics. This is done in a kiln.