A pen is an instrument for writing with ink. The earliest pens were the Chinese brush and the Egyptian reed pen for use on papyrus. Quill pens, usually made from goose feathers, were used until the mid-19th century, when steel pens largely replaced them. The modern fountain pen was invented in 1884; its nib is supplied with ink from a reservoir in the barrel by capillary action. The ballpoint pen is now very popular.