iron gall inks made with iron filings

Ingredients

mangrove wood, mangrove bark, lemon juice, rusty nails, rusty iron filings

Preparation Steps

Original Recipe Text

The source of tannins, in this case mangrove bark, is soaked in water and then boiled with iron pieces such as filings or rusty nails (p. 147). In the specific Kenyan variant collected by Ahmed Parkar, mangrove wood is used in conjunction with lemon juice and rusty nails (p. 147, note 37). The addition of the acid (lemon juice) occurs before mixing with tannins or after boiling the plants and filings to produce iron (II) ions and ensure a better stoichiometric relation between iron and tannins (p. 148).

Evidence

"The two reproduced recipes made with the addition of acid (from contemporary Kenya and al-Qalalūsī’s treatise, Fig. 7.5 A and 7.5 B respectively) have a darker colour after ageing than the one made without (by al-Marrākušī, Fig. 7.5 C)."

Remarks

The study focuses on replicating Arabic recipes where iron vitriol is replaced with metallic iron (filings/nails). The Kenyan recipe specifically utilized mangrove bark and lemon juice as an acid source. XRF analysis of these reproductions provided results comparable to those observed on ancient manuscripts (p. 148). The addition of acid prevents oxidation reactions that would prematurely turn iron (II) into iron (III), which would otherwise cause the ink to precipitate in the inkwell rather than on the writing support (p. 148).