What is the decorative plate behind a door knob called?

The decorative plate located behind a door knob or handle is commonly called a "rosette" or a "backplate," depending on its shape and style. A rosette is typically circular or oval and sits flush against the door, covering the mechanism where the knob or lever attaches. It provides a finished look and protects the door surface from wear and dirt around the handle. A backplate, on the other hand, is usually rectangular or elongated and extends further up and down the door, often accommodating both the handle and a separate lock or thumb turn. In architectural hardware terminology, the specific piece that surrounds the keyhole or cylinder is also referred to as an "escutcheon." While these terms are sometimes used interchangeably in casual conversation, "rosette" generally implies a smaller, round decorative element, while "backplate" suggests a larger, more substantial protective plate. Choosing the correct term helps when shopping for replacement hardware or describing specific design preferences to a contractor or locksmith.