Ink is a liquid containing pigments that give it colour. While today’s printer inks are often marvels of chemical engineering, the oldest inks used minerals, plant matter, and other materials to provide colour—and they’ve been in use for thousands of years.
The earliest known use of ink occurred in China approximately 5,000 years ago, when artists used soot from pine smoke, gelatin from animal skins, and lamp oil to develop a black ink used to colour the raised surfaces of pictures and text carved in stone. Other cultures used different materials to generate inks of many colours, including berries, plants, bones, and ground stone and minerals.
In ancient India, an ink was developed around 400 BC made from burned bones, tar, pitch, and other materials. India ink was often used in a sharp pointed needle that served as a pen. In Rome, an ink called atramentum was made combining iron salts with the tannins from gallnuts. This ink was blue-black when first applied, and faded to brown over time.
About 1700 years ago, the Chinese developed solid ink in the form of sticks or cakes. This ink was less messy to store and more convenient to use than prior inks had been. A piece of ink could be broken off the cake, mixed with water, and used to write. These inks are still in use with traditional calligraphy today.
Scribes in medieval Europe usually used parchment rather than paper. While paper was absorptive and made from carbon plant material, parchment was made from processed animal skins. Parchment had a greasy surface and was not as absorptive—so a new ink had to be developed. Eventually medieval scribes discovered the method of mixing tannins from plants with iron salts—a method actually used much earlier in ancient Rome. The resulting ink, called iron gall ink, was in use for hundreds of years.
The process for making ink was often quite strenuous. One recipe called for hawthorne branches to be cut in the spring and left out to dry in the sun. Later, the bark would be separated from the branches and soaked for eight days, after which wine was added and the mixture was boiled until it thickened and turned black. Afterward, the ink would be hung in bags in the sun to dry. Finally it would be mixed with iron salt and wine over a fire.
The Chinese developed block printing about 400 years before the invention of the Gutenberg press. Printing required heavier inks than handwriting did; the Chinese solution was to use pigments mixed with higher quantities of gelatin to increase the ink’s adhesiveness and lessen the chance of smudging.
The development of the printing press changed the nature of ink. At the time of its creation, most inks were designed for handwriting and were too watery to use in printers without smudging. A special ink made from turpentine, soot and walnut oil had to be developed for special use in printing presses. This ink was oily and more similar to a varnish than the typical handwriting inks of its day.
Varnishes were replaced by mineral oils in the 19th century with the advent of high-speed newspaper presses. This ink was heavy enough to withstand the printing process without smudging, and it also dried quickly on newsprint paper.
The first inkjet printer was developed in 1984, and with it came the first printer cartridge. Before ink cartridges, printer ink was delivered on messy ribbons that were difficult to change. Ink cartridges were compact, convenient, and easy to drop into the printer—and they quickly became popular. By the late 1980’s, individual household computers and printers were common. Printer ink bears no similarity to the ink found in pens; it has been carefully engineered to provide the best performance when paired with specific machines and papers.
Many printer inks contain toxic resins and chemicals that improve solubility at the expense of the environment. Today, however, that’s changing. Printer manufacturers are under pressure to develop more environmentally-friendly inks. Vegetable-based inks such as soy inks are now being developed, and some are already on the market. It’s likely that the future of ink lies in natural materials and environmental responsibility.