Restoring Historic Documents with Iron Gall Ink Corrosion

Iron gall ink corrosion can cause serious damage to historic documents. We have Pliny the Elder to thank for the ink recipe that originated in Greece. Iron gall ink was commonly created by adding iron ore and oak galls together, and cooking them over a wood stove top for several hours. The resulting ink was rich and brown. Its color could be altered with the use of additives such as copper and indigo. The visual quality and “flow” behavior of the ink could be adjusted as well by adding gum arabic and other binders. The ink was then applied with a quill pen. Recent research has revealed that the addition of copper and gum arabic in particular often lead to the most corrosive inks, which will actually burn through paper entirely, leading to “lacing,” or iron gall ink corrosion, which can irreparably damage historic documents. Above is an example. Iron gall ink corrosion can burn through paper, creating “lacing” and permanent loss of text over time.

If a paper artifact is to be treated properly, the issue of iron gall ink corrosion must be addressed during treatment, or else the problem will worsen over time and can destroy the document. Treatments that do not address iron gall ink corrosion can actually accelerate the deterioration of the inks, so it is paramount that a skilled conservator address these concerns. I am currently treating a historic recipe book for the Western Virginia Historical Society. It is an object that was declared one of the Top Ten Endangered Artifacts of Virginia in 2019. The recipe book belonged to Eliza Breckinridge Watts, a member of two prominent families with history in Botetourt County dating back to the Revolutionary War era. Eliza and her husband General Edward Watts resided near present-day Roanoke near the Barrens. Their home was called the Oaklands, one of the largest plantations in Southwest Virginia. Eliza’s recipe book is filled with iron gall ink manuscript, and evidence of corrosion was present when I performed my initial evaluation. In order to remove the free iron ions that cause the corrosion, I immersed the pages in a bath with the appropriate chelating agents. Below is a video I created explaining the process:

Washing, stain reduction and iron gall ink corrosion treatment of a historic recipe book from Botetourt County, Virginia. The book belongs to the collection of the Western Virginia Historical Society.

I will share more information about the subsequent stages of treatment for Eliza’s recipe book in a later blog post.

If you have questions or require assistance treating and preserving a paper artifact with iron gall inks, please submit and inquiry via the contact form on my website:

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