The history of ink can be traced back 4,000 years, by delving into the histories of handwriting and dyeing. Chinese and Egyptian findings each date to about the 2,500 B.C.E. These drawings began after the era of engraving on stone tablets, in which reeds and brushes could be used to apply a readily available supply of black and colored mixtures.
Carbon served as the fundamental base of early inks, either in the form of ground-up charcoal or lampblack mixed. The lampblack or charcoal was mixed into either a water or oil and was then combined with a resin and shaped into an ink stick. This process most likely had to occur just before using the ink.
By the seventh or eighth century, growths on trees rich with tannin, as the result of insect attacks, served as a primary source of ink. Mixed with iron salts, the tannin created an ink with a pale blue-gray color. The blue-gray image did not last long, as oxidation quickly turned it black. More time would have to pass before ink was able to be mixed with indigo to create a wider variety of hues.
Ink achieved its primacy in about 1550 when Johannes Gutenberg developed the movable-type printing press. Gutenberg's press enabled mass production of printed text, but it relied on carved woodblocks to produces images in ink. These woodcuts continued to be the primary form of imprinting images until the 19th century and the introduction of lithography. Minor advancements in printing occurred with the onset of the Industrial Revolution and the advent of photography but, for the most part, the means by which to transpose ink remained unchanged until the 20th century.
The main printing types currently used with ink include letterpress, gravure, lithography, silkscreen and non-impact digital printing. Unlike the first four, non-impact digital printing abandons the traditional method of using a plate to press the ink to its intended printing surface. Identified with modern PC printers, digital ink came into fashion in the late 1980s as computers became integrated into the home office. Although most modern newspapers and books continue to be printed using a lithographic method, digital printing continues to progress toward being a practical option for commercial printing.