A nib is the part of a quill, dip pen or fountain pen which comes into contact with the writing surface in order to deposit ink. Different types of nibs vary in their purpose, shape and size, as well as the material from which they are made.

A dip pen or nib pen usually consists of a metal nib with capillary channels like those of fountain pen nibs, mounted on a handle or holder, often made of wood. Other materials can be used for the holder, including bone, metal and plastic, while some pens are made entirely of glass. Generally speaking, dip pens have no ink reservoir; therefore the user has to recharge the ink from an ink bowl or bottle in order to continue drawing or writing. However, there are simple, tiny tubular reservoirs that illustrators sometimes clip onto dip pens; these allow drawing for several minutes without recharging the nib. Recharging can be done by dipping into an inkwell; however, some illustrators and cartoonists, who are the main current users of such pens, are more likely to charge the pen with an eyedropper, a syringe, or a brush, which gives them more control over the amount of ink applied. Thus, "dip pens" are not necessarily dipped. Many illustrators call them "nib pens."