Curtain rod sets can be made of many materials including- wood, metal and plastic. Curtain rods come in almost endless styles and designs. Not all curtain rods are simple straight poles; curved and hinged poles are available from numerous companies, allowing installation in bay windows and around curved walls and corners. Curtain rods can also be shaped like a crane or exhibit a swing arm design. http://www.clearskydeco.com/curtain-hardware/curtain-rod-sets/