Mihin tarkoitukseen kuulakärki kynä keksittiin?
A ballpoint pen, also known as a biro or ball pen, is a pen that dispenses ink (usually in paste form) over a metal ball at its point, i.e. over a "ball point". The metal commonly used is steel, brass, or tungsten carbide. It 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. As a result, it has influenced art and graphic design and spawned an artwork genre.
is a pen that dispenses ink (usually in paste form) over a metal ball at its point