|P.O. Box 219 Batavia, IL 60510
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 A.D., 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.