iron gall ink made with iron filings or nails instead of the more common vitriol

Ingredients

iron filings, iron nails, iron slags, gall nuts, bark from wild olive trees, mangroves, seed pods of the Egyptian thorn, witchweed, water, lemon juice, vinegar, date vinegar, manganese, gum arabic

Preparation Steps

Original Recipe Text

The source of tannins (gall nuts, bark from wild olive trees or mangroves, seed pods of the Egyptian thorn, or witchweed) is soaked in water and then either left to macerate or boiled with iron pieces such as filings, slags, or rusty nails. In some variations, an acid source like lemon juice, vinegar, or date vinegar is used to soak the iron pieces before they are mixed with the tannins, or the acid is added after the boiling of the plants and filings has occurred (p. 147-148).

Evidence

"in a recent study of Coptic manuscripts, several fragments dating from the 7th to the 10th century presented inks in which only iron and a small amount of manganese were identified using XRF (p. 146)"

Remarks

The resulting ink is described as dark brown rather than black because the exchange involves only a small number of ions (p. 146). The addition of acid after boiling helps maintain an acidic environment that prevents oxidation of Fe2+ into Fe3+, resulting in a better stoichiometric relation and a darker color after aging (p. 148). The preparation is considered more stable over time than vitriolic inks because no sulfuric acid is present (p. 148, note 38).