Making Iron Gall Ink




About: The RISD Museum encourages discovery and creative expression by connecting audiences with art and design.

This Instructable is part of a project I completed for the RISD Museum, for which I copied Luca Cambiaso’s drawing Deposition from the Cross (ca. 1570). This lesson is paired with a secondary article on how to make a quill pen.

Iron gall ink contains three ingredients, plus water: oak galls, ferrous sulphate, and gum arabic. I used a 1770 recipe that calls for two ounces of crushed oak galls soaked overnight in one pint of water, then strained into one ounce of ferrous sulphate. One-half ounce of gum arabic is added, and the mixture stirred until it is dissolved.

You can also read an article I wrote discussing my process for copying Luca Cambiaso 1570 drawing using iron gall ink.

Written by Andrew Raftery (RISD faculty, Printmaking)

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Step 1: Harvesting and Drying Oak Gall

Oak galls grow when a gall wasp lays an egg into a puncture on the underside of an oak leaf. As the larva develops, the tree secretes tannic and gallic acids, creating a round formation known as a gall nut or oak apple. These are harvested and dried. The hole from which the wasp emerged is clearly visible on each gall nut. I harvested live oak galls during the New England spring.

Step 2: Crushing Oak Gall

After drying, crush oak galls with mortar and pestle. You will need two ounces of crushed oak galls.

Step 3: Soaking Oak Gall

Pour one pint of water onto crushed oak galls. After soaking for 24 hours straining oak gall/water mixture through cheesecloth.

Step 4: Adding Ferrous Sulphate

Ferrous sulphate, historically known as vitriol or copperas, is produced by passing iron through a bath of sulfuric acid. The resulting green crystals are used to make ink.
Measure one ounce of ferrous sulphate on scale. Add ferrous sulphate to oak gall solution.

Step 5: Adding Gum Arabic

Iron gall ink, five seconds later. Gum Arabic can be added at this point. Gum Arabic—dried sap from the gum acacia tree—has extensive use as an art material, especially as the binder for watercolor and gouache. As an ingredient in iron gall ink, gum arabic adds brilliancy and substance.

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    13 Discussions


    6 months ago

    How much gum arabic, if you please?


    1 year ago

    I don't know if anyone will see this but here goes. The oak galls I have gathered so far are small, very closely bound to the twig and don't have any holes in them, probably because we are in December and I was wondering if these could be used too. I also haven't been able to find any precise information on the most efficient way to dry the oak galls, should I bury them in rice or something?


    2 years ago

    thanks for sharing this, just a quick question would ferrous sulphate tablets crushed in pestle and mortar have same effect?


    3 years ago

    As DTOM mentioned earlier.....acorns are a perfect substitute, and make Fantastic gall ink.

    The way I make it is to use an old super RUSTY cast iron pot for boiling the acorns, and no extra iron is needed at all. .....when finished, just leave the old pot outside to continue rusting.

    Although you can add honey, gum arabic, or powdered egg whites as mentioned, I've never noticed that it was necessary either.

    Just shake the bottle of ink before using, and never had any need for a binder so far, and I've been using this ink for about 5 years now.

    My end product is a JET black ink with tones of grey, and purple when thinned out.....the acorns locally that I use are Red, and Black oak acorns.


    3 years ago

    How lightfast is this ink? On a scale of 1-10 where 1 is not lightfast at all and 10 is permanent?


    4 years ago on Introduction

    along the lines of the idea presented by Edbed, it makes me wonder what would happen if you used strong black tea instead of water.


    4 years ago

    I've done this but used very strong black tea for the tannins instead of oak galls, it worked well but was a tad watery so I would recommend try to consent rate the tea more.


    6 years ago on Introduction

    Cool. Thanks.

    Ferrous sulphate is probably a fairly late variant on iron gall ink. Medieval formulas only called for iron to be dissolved intot the gall solution. In some cases, pieces of scrap iron were dumped into the solution.

    For those wanting to do this at home, galls aren't actually necessary. What you're looking for is tannin. I collect acorns, crush them, and steep them in water.

    For the iron component, I immerse steel wool in the solution. Powdered egg whites also work as a binder/thickener in place of the gum arabic. I wrote an article about this and other inks and pigments last year, for the DIY crafter demographic. I used to be active in the Society for Creative Anachronism, so it is written from that point of view. (If you want to make your own ferrous sulphate, that's covered, too; think old battery acid and steel wool.)

    (Other crafty type articles at - armor, paper, mead, medieval shoes, sundials...)

    2 replies

    Reply 6 years ago on Introduction

    And if you use acorns, you can eat them when you're done. [grin]
    (But you'll want to soak/boil and pour out several changes of water before they're really edible.)

    Very interesting. Never seen oak galls so I guess they don't happen where I live. I take a walk every day and regularly go by a park with many oak trees and I notice everything.