Historically, trumpet brooches were primarily made of bronze, in addition to brass, and less frequently of precious metals such as 925 sterling silver, often complemented by gold inlays, enamel decorations, or silver wire wrappings. While the ornate version impresses with elaborate embellishments and three-dimensional, trumpet-shaped elements, the knee version is characterized by a distinctive, right-angled bow shape reminiscent of a bent knee.