A ballpoint pen, also known as a biro or ball pen, is a pen that dispenses ink over a metal ball at its point, i.e. over a "ball point". The metal commonly used is steel, brass, or tungsten carbide. The design was conceived and developed as a cleaner and more reliable alternative to dip pens and fountain pens, and it is now the world's most-used writing instrument; millions are manufactured and sold daily. This pen's ink usually seeps through paper more frequent than other types of pens. As a result, it has influenced art and graphic design and spawned an artwork genre.