Ink-making materials
Photo: Arne Ader
Translation: Liis
Oak galls.
Oak galls or oak apples contain a great amount of tannins, and there are descriptions of how to make ink from them from the first centuries of our times. In the 18th century this ink was quite commonly used:
1 part gum arabic
2 part iron vitriol (iron sulphate)
3 parts oak galls
30 parts water
The iron compounds react with the oxygen in the air after writing on the paper, but the black colour forms only slowly during a couple of days. The oxidation continues, and after some more time the writing becomes brown. To stop this various acids were added, but these in turn made the ink difficult to see during writing, and destroyed the paper when it was stored.
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