Lexicon of Terminology for Conservation of Islamic Manuscripts

IRON GALL INK

IRON GALL INK
Ink formed by the reaction of tannic acid with an iron salt, such as ferrous sulfate (Fe`2`SO`4`). The name derives from a natural source of tannic acid, the galls formed by some species of trees in response to parasitic insect attack. However, other plant sources are also used. The ink solution oxidizes when applied to a support and is thereby exposed to air. A dark material, ferric tannate, the visible ingredient of the ink, is then precipitated onto the support.

UBL OR. 1341

Ink formed by the reaction of tannic acid with an iron salt, such as ferrous sulfate (Fe2SO4). The name derives from a natural source of tannic acid, the galls formed by some species of trees in response to parasitic insect attack. However, other plant sources are also used. The ink solution oxidizes when applied to a support and is thereby exposed to air. A dark material, ferric tannate, the visible ingredient of the ink, is then precipitated onto the support.

AUTHORS: PAUL HEPWORTH AND KARIN SCHEPER

TERMINOLOGY