21 is the fourth best-selling pen of all time.
 Reed pens, quill pens and dip pens, which were used for writing, have been replaced by ballpoint pens, rollerball pens, fountain pens and felt or ceramic tip pens
										=== Historic ===These historic types of pens are no longer in common use as writing instruments, but may be used by calligraphers and other artists:A dip pen (or nib pen) consists of a metal nib with capillary channels, like that of a fountain pen, mounted on a handle or holder, often made of wood

