Iron Gall Ink

Definition: Iron Gall Ink is a highly acidic ink produced from oak gall nuts. It fades to brown in the light, and its corrosive effects cannot be halted. The acids in iron gall ink react with the collagen in the surface of parchment, making it highly permanent, unlike carbon inks which easily rub off the impervious surface. However, the acids can also destroy documents, creating a challenge for historians, who have to read the holes burnt in ancient papers, and conservators, who need to find a way to neutralize the acid. For this reason, it is advisable to choose a modern archival ink in preference to making this traditional ink.