Oak Gall Ink

Did you know that Oak trees are part of our written history – via oak gall ink? A recent post on our Facebook page about this caused quite a stir, so we thought we would tell you more.

How is it made?

The gall wasp (or some other insects) leaves an injection of chemicals into an oak tree gall (a round, fibrous growth), therefore gallotannic acid is created. They water this down to make tannic acid. Mixed with iron sulphites, it created ink. The ink is waterproof and gets darker with age, making it perfect for important documents.

Used from the 12th century all the way to the 19th century, almost all surviving historical documents were likely to have been written with ink make from oak trees. It was popular because the ingredients were readily available and cheap. Primarily used for important documents as the words or images were hard to remove.

Why is it important?

Here are some of the most central texts written during that period:

  • Codex Sinaiticus (hand written Bible)
  • Magna Carta
  • Mayflower Compact
  • US Declaration of Independence
  • Guy Fawkes confession
  • Shakespeare’s Will

We are fascinated by oak gall ink. If you are too, there is an excellent article by the National Archive here.


The oak tree is perhaps the most popular of native British trees, we certainly have more oak planted than any other tree at Granville’s Wood. You can grow from an acorn, do a ‘float test’ first, planting those that sink. Oaks grow best in ground already proven, so where you see oaks thriving, that is the right soil.

Saplings need plenty of water and plenty of room. They put down deep roots, so make sure they have room to grow. Remember that oak trees can live for hundreds of years, so you will are leaving a wonderful legacy for generations to come.