Ink
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.
The first inks were carbon inks, made from soot, which is 80% carbon, water and gum arabic. Red ink would need iron oxide (such as haematite) from ground rocks instead of soot. Later, in Europe, people used iron gall ink. This is the kind of ink Johann Sebastian Bach and Leonardo da Vinci used. Now ink colours are produced by man-made dyes.
A disadvantage of many kinds of ink is that they may smudge when wet, spoiling the picture or writing. If water-based ink is used, the writing situation needs to be stable, with the writer seated at a table. Ink in a ballpoint pen (biro) is a kind of gel. It 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. Therefore, ballpoint pens can be used in a wider range of circumstances compared to water-based inks.
== Ink Media == <gallery widths='160px' heights='100%' mode='traditional' caption=''> File:Füller-tinte hg.jpg|Bottles of ink from [[Germany]] File:קלף, נוצה ודיו.jpg|A parchment quill and ink. Klaf, Kulmus & D'yo File:Ganesha ink.jpg|Ink drawing of [[Ganesha]] under an umbrella (early 19th century). Ink, called [[Masi (india ink)|''masi'']], an admixture of several chemical components, has been used in India since at least the 4th century BC. The practice of writing with ink and a sharp pointed needle was common in early [[South India]]. Several [[Jain]] sutras in India were compiled in ink. File:Oak galls and iron(II) sulfate - California State Archives.jpg|Oak galls and iron(II) sulfate File:Tintenstrich-detail 2.jpg|Magnified line drawn by a [[fountain pen]]. File:Inkstick.jpg|Chinese [[inkstick]]; carbon-based and made from [[soot]] and [[animal glue]] File:Un électeur avec l' encre indélébile au pouce, après son vote dans un centre dans la commune de la Tshopo à Kisangani (6418380139).jpg|A voter's thumb stained with indelible ink </gallery> == References ==
- 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 (10): 1476–1478, doi:10.1021/ed083p1476.
