Wednesday, April 3, 2024

Iron and Oak

Iron Gall Ink!

This is probably one of the most widely used historic inks we know about.  The earliest surviving manuscript using iron gall ink is the Codex Sinaiticus, dating from the 4th Century! It was used by Da Vinci, Shakespeare, for the Declaration of Independence, and in countless versions of the Bible.  There were slight variations, but this ink was so prevalent because it's so easy to make with ingredients that are widely available.

This ink is superior to the carbon ink that predates it in that, because of its acidic nature, it etches itself into the parchment, becoming permanent and will not smudge.  However this very benefit can also cause long term corrosion. There were actually many iterations of this general recipe.  Essentially, scribes would use what was available to them.  Instead of apple cider vinegar like I used, they may have used wine or beer, or even just allow the gall solution to ferment!  (4)


1. Iron: just a little chip would do.  Traditionally this could have been picked up from any old, bent nail or perhaps filings from the blacksmith's shop.  Today we can even use the iron component in steel, but never use anything galvanized for this process!  The chemical reaction we're after would cause harmful off gassing with galvanized steel. 

2. Vinegar: any vinegar will do.  We want the acidity that the iron can dissolve into.

3. Oak Galls:  These look like thin, paper-like balls attached to leaves that are very brittle.  You will often find them on the ground under oak trees, though there are varieties that grow on rose, blackberry, or raspberry vines.  They are produced by the gall wasp as part of their incubation process.  By the time you find the galls on the ground, the wasp has long since left.  Oak galls contain very concentrated tannins (tannic acid). (1, 2)

4. Enough water to cover the galls in a pot.


1. In a jar, cover the iron with vinegar and allow to dissolve and create iron acetate for two to three weeks.  This is sometimes called "vinegroon" or "coperose".  

2. When your iron vinegar is ready, put about a handful of galls, slightly crushed in a pot and cover them with water.  Allow to simmer on the stove from 20-30 minutes.  Once this has cooled you can strain the remaining gall from the liquid.  

3.  In a small jar, combine equal parts (this ratio may vary) vinegroon and gall tincture.  As soon as they come into contact, you can see the chemical reaction of the iron acetate with the tannic acid to create the deep black ink from the phenolate complexes! (3)  Below are three clips: the first is the iron vinegar, the second is the gall solution, and the third is the magic (chemical reaction) when you combine!

4. Ready for use in your painting or calligraphy!  Most scribes will thicken this solution with a little gum arabic.

But the thing that makes this recipe even more versatile?  You can use almost any tree product for this, because almost anything a tree produces contains concentrations of tannins!  You could use nuts, cones, bark, roots, or seeds!  

There is a recipe in the National Archives of the UK from 1483 (C 47/34/1/3). While the resource (5),  it basically calls for equal parts water, iron vinegar, galls, and gum arabic.  Another from the early 15th C. resides in the Cambridge University Library (MS E.e.i.15) and describes an ounce each of galls, "coperose" (Iron acetate), and gum arabic crushed and added to a pint of rain water, stirring daily for three days.  


1. Day, E. and Dellinger, T. (5-16-2022) "Galls Made by Wasps" VCS Publications/Virginia Tech.  Last Visited 4-1-24 from,are%20attacked%20by%20gall%20wasps.

2. U.S.F.S. "Tannins" United States Forest Service.  Last Visited 4-1-24 from

3. Thompson, R. (8-8-2022) "Iron Acetate Solution Prepared from Steel Wool and Vinegar for Ebonizing Wood" Research Square.  Last visited 4-2-24 from

4. Gupta, A. (2-25-2021) "The Ins and Outs of Iron Gall Ink" American Philosophical Society.  Last visited 5-2-24 from,is%20blue%2Dblack%20and%20permanent.

5. Peverley, S. (2024) "Iron Gall ?Ink: A Medieval Recipe" Professor Sarah Peverley.  Last visited 4-3-24 from,it%20is%20ready%20to%20use.

6. White, T. (1-27-2021) "A Medieval Ink Recipe."  St. Edmund Hall, University of Oxford.  Last visited 4-3-24 from

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