iron-gall-ink

Ingredients

gallic acid monohydrate, ferrous sulphate hepta hydrate, copper sulphate penta hydrate, gum Arabic, saffron, alum, oak galls, NaCl, acetic acid

Preparation Steps

Original Recipe Text

The preparation involved multiple groups of experiments. Group 1: 100 ml distilled water, 1.0 g FeSO4.7H2O, 1.0 g gum Arabic, and varying amounts of gallic acid (0.19g, 0.45g, 4.0g) (p. 35). Group 2: Added CuSO4.5 H2O in mole ratios of 0.01, 0.4, and 0.8 relative to iron (p. 36). Group 3: Added 5% saffron solution (3.32 ml, 20 ml, 0.6 ml) (p. 37). Group 5 (historical recipes): Ink 12 was made from 16 mL water, 1 mL 10% acetic acid, 1.0 g powdered oak galls, 0.53 g FeSO4, and 0.53 g gum Arabic (p. 38). Ink 13 was made from 66.8 mL water, 7.688 g powdered oak galls, 2.528 g FeSO4.7H2O, 0.2 g NaCl, 2 mL 10% acetic acid, and 0.318 g alum (p. 38).

Evidence

"The main ingredients used in the black inks are gallic acid monohydrate (Ga) (C7H6O5.H2O, MW: 188.14g/mol, Aldrich) and ferrous sulphate hepta hydrate (FeSO4.7H2O, MW: 278.02g/mol, Merck)."

Remarks

The study investigates the impact of Fe/Ga ratios and additives like copper and saffron on the corrosion of cellulose. It notes that the mole ratio of iron (II) sulphate to gallic acid typically varies between 1 and 4 in Ottoman recipes (p. 34). Analytical tests showed that measured changes in chromatic values (delta a* and delta b*) indicate the degree of cellulose oxidation (p. 31).