carbon pigments; ferrous gallate

Ingredients

soot, charcoal, gum arabic, protein glue, tannins, tree bark, gallnuts, iron(II), vitriol, chalcanthum

Preparation Steps

Original Recipe Text

Carbon ink: Consists of soot or pulverised charcoal mixed with a water-soluble binding medium such as gum arabic (typical in Egypt) or protein glue (p. 41). Plant ink: A solution of tannins extracted from tree bark or gallnuts (p. 42). Iron-gall ink: Produced via the reaction between gallic acid (sourced from gallnuts) and vitriol (a source of soluble iron and hydrated metallic sulfates), forming the black precipitate ferrous gallate (p. 42). Mixed ink: Categorized into two types: (1) carbon ink mixed with iron-gall or plant ink (p. 44); (2) carbon ink with copper-based substances like chalcanthum (p. 44).

Evidence

"The most common ink used in the Cairo Genizah is black ink – although the category of black ink includes what are now “brown inks”, since the current appearance of an ink can result from ageing, degradation and restoration. Black inks in the medieval Islamic world can be divided in four distinguishable categories: inks based on soot or charcoal (carbon), those based on plant material, those based on iron-gall, and mixed inks."

Remarks

The study investigates a corpus of 391 manuscripts (498 documents) focusing on the 11th century (p. 26). The author highlights that 'brown' inks in the Genizah are often the result of aging or degradation of originally black inks (p. 41). The presence of satellite impurities (manganese, copper, zinc) in the vitriol used for iron-gall ink allows for the differentiation of specific ink batches (p. 43). The author specifically notes that the characterisation of removed ink in palimpsests was excluded as unreliable (p. 26).