How to make Oak Gall ink like Leonardo Da Vinci

Maya Keshet
MAKE by Maya Keshet
5 min readFeb 22, 2023

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Oak gall ink is as black as a black can get. It is permanent, indelible, waterproof, and very hard to wipe away, as it infuses into the fibers of the paper rather than drying on the surface.​

Also called iron gall or registrars’ ink, oak gall ink dates all the way back to 1200AD. It was used by kings and officials for formal documents and contracts, and was the ink of choice for many artists, among them Leonardo De Vinci, Rembrandt, Vincent Van Gogh, J.S. Bach, Beethoven, and Mozart, to name a few. It is stable and is actually pretty easy to make, once you obtain the ingredients.

How does it work​

It all starts with a tiny wasp, the oak gall wasp. When an oak gall wasp lays its eggs on the shoot of an oak tree (different types of wasps prefer different types of oaks), the tree responds by forming a tiny sphere that surrounds the eggs. This is called the oak gall. The larvae are safe inside their oak gall home, and the tree keeps responding to the tiny invaders by secreting tannings, materials rich in color. When the baby wasps are ready to leave, they drill a hole or a number of holes in the gall and fly away to begin living their lives as full-grown wasps. The galls are left on the tree. What a treasure for ink makers!

Dry oak galls with holes. The holes indicate that the baby wasps are no longer inside

Galls aren’t always easy to find. You can purchase them online, and there’s nothing wrong with that. I took advantage of a recent trip to Israel to go foraging for galls and was lucky to find some. If you choose to do the same, be sure to pick them when they are brown, not green, and that they have holes in them, as this means the baby wasps have left, making the holes on their way out. In addition, note that the galls double in weight when they’re wet, so make sure they are dry when you weigh them, or you may not have enough to make the ink.

The deep rich black of oak gall ink comes from chemical reactions between the tannings in the galls, ferrous sulfur, and the oxygen in the air.

Before you start

Oak gall ink is highly acidic. You should use gloves, and, of course avoid any contact with the eyes, mouth, etc.

Since the acidic ink infuses into the fibers of the surface, it will eat away at plant-based paper over time. As the ink has been around for “only” about a thousand years, no one knows how long it will last, but we can assume it will last for at least a thousand years, as long as you use it on non-plant-based paper, such as vellum. However, vellum is dried animal skin and I am vegan, so I experimented with highly alkaline paper, and am currently mostly using stone paper (look it up, it’s very cool).

Whatever media you choose, consider scanning your work, using a high-quality scanner. I have found this to be a very good investment if you can afford it and want to purchase one. If not, use your phone camera to save a copy of your work.

Materials needed to prepare your ink. I replaced the liquid gum arabic in the photo with flakes

Materials

2 ounce (57g) dried oak galls
2 cups (475 ml) water
1 ounce (28g) grounded ferrous sulfur (in medieval times it was called copperas)
2–3 flakes gum arabic (for brilliancy and body)

A glass jar with a lid
Mortar and pestle (I changed to a clean spice grinder, which from now on will only be used for making ink!)
Old pot (also only used to make ink)
Fine cheesecloth

Methods​

1. Grind the dried oak gall with a mortar and pestle (or spice grinder). Place the powder in the pot.

2. Pour the water into the pot and leave the crushed galls to soak for a few days.

3. Your pot now contains a brown solution of gallic and tannic acid. Use the cheesecloth to strain the solution into the glass jar.

4. Add the ferrous sulfur (copperas) to the jar. The solution will turn black.

5. Add 2–3 flakes of gum arabic and close the lid.

6. Congratulations! You now have your very own oak gall ink.

Final notes

1. The ink will darken on paper as it reacts with the oxygen in the air.

2. Store your ink in a lidded glass bottle or other container away from light.

How utterly amazing it is to be able to combine ancient practices with new methods and technologies. These are truly wonderful times we live in, don’t you think?​

I hope you enjoyed my first blog. To those of you who decide to make your own oak gall ink, happy ink making!

You are all welcome to visit MA.KE by Maya Keshet website at: https://www.mayakeshet.com

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Maya Keshet
MAKE by Maya Keshet

Founder & Owner of MA☀️KE by Maya Keshet. Entrepreneur; Author & illustrator of Children’s books; Artist. 🖼 View Portfolio: mayakeshet.com/portfolio