Ink is a liquid that is used to write, draw, print, or make marks. The word ink is from Latin and means "colored water". Ink is used in pens, in some computer printers, and in printing presses. In some countries, people write by using ink and brushes. People usually write or print using black ink, but ink can be any color. The first ink was used in Egypt about 2600 BC.
A disadvantage of many kinds of ink is that they may smudge when wet, spoiling the picture or writing.
Ink in a ball point pen is held in a thin long cylinder (tube) inside the pen. The ink does not fall out of the cylinder as it sticks to the sides of the tube.
- Martín-Gil, J.; Ramos-Sánchez, M.C.; Martín-Gil, F.J.; José-Yacamán, M. (2006), "Chemical composition of a fountain pen ink", Journal of Chemical Education 83: 1476–1478.