Pen and ink refers to a technique of drawing or writing, in which colored (this includes black) ink is applied to paper using a pen or other stylus. It may be used as a medium for sketches, or for finished works of art. Pen and ink also lends itself to fine writing and calligraphy.
Different types of pens produce distinctive types of lines. Some, such as the crow-quill dip pen, produce slender and delicate lines. Other pens have a broader nib which can produce both thick and thin lines. Fountain pens and ballpoint pens are often regarded by many artists as being insensitive instruments or even not true "pen and ink" work, but are often useful for sketching in conditions in which a pot of ink would be a spill hazard. Many technical artists prefer the Rapidograph series of technical pens, which produce lines of extremely regular width.
In art, pen and ink was originally used for quck sketches, often with a high degree of abstraction. George Romney produced a number of notable ink sketches of Emma Hamilton which are noted for the economy of his strokes, in which he produces instantly recognizable figures with a dozen lines.
Later artists developed the pen and ink drawing into a finished artform, and many interior illustrations in books and magazines are done in pen and ink because they do not require halftone screening, unlike continuous tone techniques such as ink wash or painting.
Pen and ink calligraphy was raised to a high level in Arabic, since Islam forbids the representation of living beings. In some forms of Arabic calligraphy, the letters were delicately formed to suggest an image related to the meaning of the phrase being written, without being an actual image of a living being.