Making ink from oak galls

By Jean Duncan

Oak galls are small spherical growths that form on oak trees where the gall wasp lays its eggs in the buds of the tree. The tree grows tissue around the egg which protects the wasp until it hatches, leaving a hole. Watch out for a hole in the gall before harvesting.

The end of the summer is a good time to harvest, I find the galls are easier to spot once the leaves have fallen. If you can’t find them, you can buy oak gall powder/whole oak galls online [1].

Drawing Ink

With the addition of iron, oak galls make a permanent ink. The method involves a reaction between tannic acid extracted from the galls and ferrous sulphate. The ink would once have been used with a quill and later a dipping pen.

Oak gall ink can still be seen on early manuscripts, though many are damaged due to the acidity of the tannic acid, which eats away at the natural fibres of paper, parchment or vellum [2]. To avoid such damage, recipes now use less ferrous sulphate.

Wet oat gall ink on paper (Jean Duncan)

Recipe This makes 250 ml of ink.

To make a permanent oak gall ink you will need ;

  • 30 g of whole oak galls or oak gall powder.
  • Pestle and mortar
  • Scales
  • Rain water
  • Muslin
  • 15 g ferrous sulphate powder *
  • 7 g gum arabic solution
  • Glass jar for storage.

*Can be purchased as blue green crystals or white powder.

Colour from oak galls can be used alone, but the addition of ferrous sulphate makes the ink permanent and black (Jean Duncan)

Method

  1. Crush the oak galls with a pestle and mortar or put them in a bag and mash them with a hammer.
  2. Add 30 g oak gall powder to 25 ml of water and leave to soak for 24 hrs.
  3. Strain the liquid through the muslin.
  4. Mix the ferrous sulphate into the strained solution.
  5. Add the gum arabic and stir well
  6. Add oil of cloves or any other essential oil to help it keep for longer and store in the fridge. 
  7. Try using the ink with a pen and a brush to see that it flows well, if the ink has a dusty surface add more gum arabic.

It is worth experimenting with washes of ink, as it turns blacker when it reacts with oxygen from the air.

Oak gall ink reacting with barley ink made from orzo coffee grounds (Jean Duncan)

I wanted to make my own inks and watercolours to help create a sense of place in my drawings through botanical colours from my local environment, while consciously moving away from synthetic printing colours which are often unpleasant to use, toxic and harmful to people and the environment.

The photograph above shows a blend of colours produced on paper by oak gall ink and barley ink, the latter from orzo, a caffeine-free drink made from barley.

Colours from oak gall, onion skin and coreopsis – drawing by Jean Duncan

There are many artists and artisans working in this way and small businesses are leading the way in using locally sourced materials and natural dyes to make cloth that at the end of it’s life can be put back into the earth as a biological nutrient rather than a pollutant. I have given links below to two Fibreshed businesses working in this way [3, 4] and to an article on making ink from up-cycled coffee grounds [5].

Hand-bound sketchbook with oak gall, indigo and ochre cover

[1] To buy oak gall ink: George Weil fine art and craft supplies.

[2] Sakura Tohma (2015) Making and testing Iron Gall ink. West Dean College web site.

[3] Bristol Cloth – wool and botanical inks: South West England Fibreshed.

[4] More Fibreshed – Wool from the border between the Yorkshire Dales and Cumbria, : Laura’s Loom.

[5] European Horizon magazine: Eco espressso and upcycled inks set to make coffee greener. Some interesting facts in this article: black printing ink is more expensive than Chanel No 5, and the daily ‘waste’ in coffee grounds is equal to the weight of three Eiffel Towers!

Jean Duncan is based in Fife. See her web site at JeanDuncanArtist. Jean has worked with the Living Field on many projects, exhibitions and events – her work is profiled at this Living Field page.

The photographs below are of an oak gall and oak leaf from the Living Field collection

Oak gall in late June (www.livingfield.co.uk))
Oak leaf (www.livingfield.co.uk)

Creative metalwork

David Brown is a farrier, based in Perthshire, with decades of experience in shoeing horses and fabricating metal.

In recent years, he’s been delighting family and friends with craftwork, whether wood-fires, garden ornaments or house-signs, all made from a collection of rods, plates and cylinders.

Examples of his work can be seen online [1] . The photograph below shows some of the parts being combined to make a house-sign .

Earlier in February, the Living Field went to find out how David works the metal into lettering and complex shapes of plants and animals.

It’s all done at a workshop within an old stone outbuilding in the Braes of the Carse between Dundee and Perth.

Firing scrap

The first thing noted was that the raw materials are mostly from unwanted or scrap metal. Take the rods, tied in bundles in the photograph above. They became unfit for their original purpose in the construction industry and would have been thrown away. Yet they are ideal for making things like ornamented pokers and lettering.

To become malleable, the rods are first fired in the forge until white hot, then the hot end is placed on the anvil ready for the hammer.

The end of a white hot circular rod was beaten with a hammer into an oblong (top left), which was then cut with a hand-held circular saw (top right) to form a sort of ‘tuning fork’; the rod was reheated and the prongs bent in various ways (right middle and lower). Another rod was left uncut, but twisted into a spiral around itself (lower middle and left) to form the holding end of a poker or similar implement.

Hammering, sawing, bending, twisting

A range of techniques can used to create shapes out of the fired rods. First, the rods are usually beaten with a hammer to ‘flatten’ the last few inches of the rod into an oblong.

When cool, the flattened ends can be cut with a circular saw to form two prongs, like a tuning fork. The rod then goes back in the forge until it’s white hot again and in this form, the two prongs can be bent or hammered into shape.

Or the white hot rod can be left as a cylinder, but twisted round a ‘plug’ inserted into the anvil or held in a vice and curled into a spiral.

Demonstration of the plasma cutter: the shape of a horse’s head was drawn on a strip of metal 10 cm wide and about 1 cm thick; one end of a circuit was clamped on the metal; the cutter was turned on and moved over the outline, cutting through the metal with ease. It only took a minute or so from start to finish.

Power of the plasma cutter

Shapes are usually made from discarded steel or iron plate. An outline is drawn on the metal, then a hand-held plasma cutter traces the shape to release it from the plate. A powerful thing, this plasma cutter ….. and it makes a cascade of sparks!

The shape can then be re-heated and bent, cut or hammered to add spirals and other patterns.

From discard to craftwork

It was heartening to see David’s positive efforts to turn waste metal into things useful and ornamental. Here’s two examples.

In the panel above, discarded metal discs (top right) were first cut radially into several segments, some taken out to near the centre, those remaining moulded into the form of leaves or petals, given texture by repeated blows from a special hammer. When aligned on a central rod, the discs combine into whorls of leaves or flowers.

In the lower photographs, metal was taken from an old calor gas cylinder, flattened and cut into the form of a hare.

The workshop is a place of fire, sparks, hammering and hot metal – amazing to see it all. And there is little duplication: each piece is hand made and unique.

[1] Knapp Forge and Flora – a page on facebook.

Ed: the Living Field thanks David for the invitation to his workshop and forge and for demonstrating some of his metalworking techniques.