What is the term for a patent that protects the appearance of a product?

A patent that protects the appearance of a product is a design patent.

In U.S. patent law, a design patent protects the ornamental appearance of an article of manufacture. The protected subject can include an object’s shape or configuration, its surface ornamentation, or a combination of both. Examples include decorative features of furniture, jewelry, containers, tools, and graphical user interfaces.

A design patent differs from a utility patent, which protects how an invention works or is used. A design patent does not generally cover functional features dictated solely by performance. The drawings in the patent are crucial: solid lines usually show claimed features, while broken lines commonly indicate environmental structure or unclaimed portions.

Design patents are also distinct from provisional patents, which are temporary application filings rather than a separate kind of issued patent, and plant patents, which protect certain distinct and asexually reproduced plant varieties. In the United States, design applications filed on or after May 13, 2015, generally receive a 15-year term from grant.