|Address||Flinn Scientific Canada, Inc. 175 Longwood Road South Hamilton, ON L8P 0A1|
All ink has two basic ingredients—a liquid and a source of pigment for color. The ancient Egyptians and Chinese used a very simple ink composed of soot mixed in water or vegetable oils. By the 9th century AD, medieval Europeans were making ink using a slightly more complex process of mixing tannic acid (extracted from oak galls) with an iron salt. This was called iron-gall ink. In this activity, a simpler version of iron-gall ink is made using ordinary tea bags.