A patina is the special surface that forms on metal, wood, or leather as it ages and is used over time. On copper or bronze, patina appears as a greenish coating that develops after years of exposure to air and weather. The Statue of Liberty's distinctive green color is patina that formed naturally on its copper surface over decades.

Patina isn't damage or dirt that needs to be cleaned off. It's a transformation that many people find beautiful because it tells a story of age and use. An old leather jacket develops a rich, worn patina that shows its history. A bronze statue in a park slowly changes color as its patina develops. Antique furniture often has a warm, mellowed patina that can't be faked or rushed.

The word can also describe the character that anything gains through age and experience. Someone might say that a beloved old library has “the patina of history,” meaning it feels rich with the passage of time and the thousands of people who have used it. While new things are shiny and perfect, patina represents something deeper: the visible evidence that something has lived, been used, and endured.