What is iron gall ink?
Iron gall ink is composed of four primary ingredients: tannin, iron (ii) sulfate, gum, and a solvent.
While the earliest examples of iron gall ink may date to the first centuries CE, it was most often used from the Middle Ages through the late 19th century, with a few examples appearing as late as the 1970’s. It was used throughout Europe, the Middle East, and later the Americas. Iron gall ink replaced carbon-based inks more commonly used in early centuries; these inks were made by collecting soot from burned materials and holding the soot in suspension with water and gum. Carbon-based inks were adapted and used alongside iron gall ink, perhaps most notably in the production of the Gutenberg Bible.
Click on the sections below to explore the various facets of iron gall ink—its composition, how to make it, various different recipes, and the conservation concerns that make treating documents containing iron gall ink an ongoing challenge.
Duration: Spring/Summer 2020 for ALA's Preservation Week
Curated By: Sabrena Johnson, Conservation Librarian