A fountain pen is a nib pen that, unlike its predecessor, the dip pen, contains an internal reservoir of water-based liquid ink. The pen draws ink from the reservoir, through a feed, to the nib and deposits it on paper via a combination of gravity and capillary action. Filling the reservoir with ink may be achieved manually, or via an internal filling mechanism which creates suction to transfer ink directly through the nib into the reservoir. Some pens employ removable reservoirs in the form of pre-filled ink cartridges. A fountain pen needs little or no pressure on the nib to write. World Fountain Pen Day is celebrated on the first Friday of November every year by the lovers of fountain pens.