Both are warm copper alloys with distinct character. Brass, copper and zinc, is brighter and more golden and takes a high polish, ideal for a refined interior staircase. Bronze, copper and tin, is warmer and browner and weathers to a stable patina, the traditional choice for exterior and architectural work. On a Medina home we often use polished brass indoors and silicon bronze outdoors, and we help you and your designer choose for each application.