Acorn Cap Ink

Acorn Cap Ink

After our fun with the Oak Gall Ink experiment, we decided to have a look at other sources of ink from nature.

Inks are made up of a colour, normally some sort of water-soluble colour suspended in water and mixed with a binder. Binders are a glue-like substance that helps the ink adhere to the paper.

We were aware that acorns were quite high in tannins, and would be a good source for ink, however, we used our acorn collection to make some acorn coffee, flour and a nut brittle so only had the caps to hand. We had seen a source online stating that you can get a silver ink from the caps of acorns, so we decided to make do with what we had and see what happened.

This ink doesn’t need an iron solution, so we simply started by taking a handful of caps, covering them in distilled water (we didn’t have fresh rainwater) and then we let them simmer on the stove for an hour or so to extract as much colour as we could.

After cooling slightly, we strained the caps and then added some gum Arabic powder (binder) to the solution and stirred to mix. Gum Arabic is the hardened sap of a few different tree species most notably the Acacia tree. It is an emulsifier, helping to keep the pigment suspended in the liquid, helps with the flow of the ink, will help to keep the marks and lines on paper clearer and sharper, and will thicken the solution up.

A few drops of clove oil ( or vinegar) will help acts as a preservative, thought the clove oil smells nicer.

It would be best to keep refrigerated to prolong shelf life however all my inks are not kept in the fridge to see how long they will last.


Handful of acorn caps covered in 50 ml of water (just enough to cover the caps) boiled up replacing any lost water for approximately 1 hour. Cool slightly and strain.

A per the attached pictures, I swatched the ink at this stage. I then added 5g of Gum Arabic and then another 5g until I was happy with consistency.

1 drop of Clove Essential Oil.

"This is the Lord's doing; it is marvelous in our eyes" Psalm 118:23

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