iron-gall-ink

Ingredients

tannin (gall nuts), vitriol (copperas/melanterite/chalcanthite), Gum Arabic, fluid medium (water, wine, beer, vinegar), indigo, logwoods, saffron, henna, pomegranates, crystalline sugar, alum, rose-water

Preparation Steps

Original Recipe Text

Iron-gall ink is produced from four main components: tannin, vitriol, Gum Arabic, and a fluid medium (p. 10). Tannins are extracted from galls (like oak galls) via boiling or fermentation (p. 12). Vitriol (iron or copper varieties) reacts with gallic acid to form a ferrous gallate complex (p. 22). Other additives included sugar for viscosity, alum, and various colorants like saffron or henna (p. 16).

Evidence

"Figure 1.2 Sample of iron-gall-ink"

Remarks

The ink is initially pale or light gray upon preparation and turns dark blue after application to paper due to oxidation and the formation of a ferric pyrogallate complex (p. 20, 26). The presence of excess iron (II) ions and sulfuric acid as a byproduct is cited as a major cause of paper degradation (p. 16, 22).