Ink is a type of liquid containing many pigments and dyes, which are used for coloring to bring out an image. Ink may be used either for writing or drawing with brush or pen respectively. Ink may also be of the thick variety, which is used in letterpress and lithographic, printing.
The Egyptians were one of the earliest to have used ink. It consisted of many natural dyes from metals, beans, seeds and even from squids. India ink started in Asia and is black. The old school of painters used walnut ink and or iron gall ink.
Some sort of adhesion quality is essential for inks. These adhesions are known as resins or agents that bind in ink that is water-based. Pigmented ink is best for printing on paper because it stays on the surface and thus less ink is required to make the mark.
Apart from adhesives the main components of ink comprise of pigments. Pigments are all about hue, saturation point and quality of brightness. It all depends on the source as well as the type of pigment. However, ink that is based on dye is much stronger than those based on pigments. But the disadvantage is that the dye, since these are dissolved in liquid, has a tendency to drench the paper. Thus not only is it less efficient but it blurs the image making the quality of the produced product poor. To solve this, dye-based ink is now made with solvents that rapidly dry out. Sometimes the methods of printing allow for quick drying. Another angle of approach is to use hard paper or having the paper coated with a charge. Another term used in the world of ink is cellulose. This is the material from which paper is made. It is so charged that it computes well with both the surface and the dye. The name of such a compound in ink-jet printing inks used commonly today is polyvinyl pyrrolidone. There are however advantages and disadvantages. On the one hand it leads to optical brightness but on the other it is more susceptible to the effects of fading.
Ink made its debut in the history of mankind about five thousand years ago in China. Initially it was used for blackening raised portions of pictures and texts on engraved stones. The components of this early ink were soot and animal-based gelatin. Other countries developed many types and colors of ink from berries, minerals and various plants. Pine smoke and lamp oil were also used. About one thousand six hundred years ago ink was popularly made from iron salts, mixed with tannin and acid. The color was bluish black. Time turned it into a dull form of brown color. In the Middle Ages sheepskin parchment was used for writing. In the 12th century drying hawthorn branches, which were then pounded before being soaked for eight days, formed ink. The concoction was boiled in water until the paste thickened and blackened. This ink was then poured into bags dried. Finally this dried stuff was mixed with iron salt and wine over a fire.
Guttenberg developed a new type of ink during the 15th century to go with his printing press. At that time the two prevalent types of ink were Greek and Roman and neither could stick to the surface of the paper meant for printing. The solution consisted of a type of ink made from soot and turpentine mixed with walnut oil.
The modern world and the ball point together with the computer age are bringing about changes daily in the world of ink. A word of caution should be kept in mind. Ink is dangerous if it is ingested.