iron gall ink

Ingredients

iron, gallotannates

Preparation Steps

Original Recipe Text

The iron gall ink described consists of iron (III) gallotannates (p. 144). The study focuses on the treatment of this ink using calcium phytate solutions (pH 5) and calcium bicarbonate (0.011M, pH 6) to complex free iron (II) ions and prevent catalyzed oxidation (p. 138, Table 2.1). Ethanol (EtOH) was used in mixtures (e.g., 1:1 EtOH:RO) to limit the solubility of ink components and prevent bleeding during aqueous washing (p. 143).

Evidence

"This project uses nine original iron gall ink documents and compares various treatments with the combination of calcium phytate and calcium bicarbonate."

Remarks

The documents were assessed to be in ICN condition rating 1 (initial stages of ink corrosion). µXRF established iron as the only major element in the ink (p. 141). Treatments including 1:1 EtOH:RO produced the least bleeding but were less effective at removing corrosive iron (II) ions (p. 143). The combined calcium phytate and calcium bicarbonate treatment (#16) was found most effective for long-term protection (p. 144).