Intriguing black
“Ink has ensured the transmission of our cultural heritage”:
Monique Zerdoun Bat-Yehuda
It has been a long time since I read a book (monograph) devoted entirely to black ink. A book full of history, recipes and interesting facts, all about black ink from all over the world. How about an overview of inks and recipes from China, Korea, Japan, Egypt, and the use of ink in Jewish and Islamic culture? The author also devotes considerable attention to black ink from Europe between the 4th and 17th centuries. A true masterpiece about the black ink used by writers throughout history until 1600.
The title of that book is: ‘Les Encres Noires au Moyen Âge jusque’ à 1600’ (Black Inks in the Middle Ages until 1600) and was written by Monique Zerdoun Bat-Yehouda, published by CNRS Editions in Paris in 1983. 435 pages.
I struggled through it with my secondary school French and what a wonderful work it turned out to be. However, it is only available in French and has not (yet) been translated. All the more reason to keep French in the secondary school curriculum. (!)
The book is still available for purchase but can currently be read in its entirety online:
https://www.persee.fr/doc/dirht_0073-8212_1983_mon_28_1
Why am I talking about the book? Because I wanted to learn more about black ink, as I regularly get questions about it during my workshops. In addition to the facts about black ink, I thought it would be a good idea to include instructions for making black ink in the recipe collection on my website. I will start with gallnut ink, also known as iron gall ink.
Iron gall ink
In the history of writing, there are two types of black ink:
a. Carbon-based ink.
b. Ink based on tannin and iron sulphate, also known as iron gall ink.
The earliest use of iron gall ink is difficult to trace, unlike carbon ink, which sources indicate was already in use in 2500 BC. The reaction between tannin-containing writing materials and iron salts appears to have been known since ancient times. Pliny describes an experiment in which he dripped a solution of iron salts onto a piece of papyrus dipped in tannin, which immediately turned black. There is also a recipe from the 5th century for making such ink. However, it would be centuries before iron gall ink became the most common ink for writing and replaced carbon ink.
We can say that iron gall ink had become the most important ink for writing manuscripts in the late Middle Ages. This transition was partly due to the high demand for ink in cities, with their increasing use of writing. The increase in universities, trade, etc. created a high demand for written documents and therefore also for ink. The production of iron gall ink in large quantities is much simpler than that of carbon ink. However, the use of iron gall ink did lead to a significant problem: ink corrosion. Discolouration and brittleness of the carrier made the writing illegible. This problem occurs mainly with paper where the cellulose is affected by acidification and oxidation. The acidification is a result of the sulphuric acid present in the ink, while the oxidation is caused by the iron present. Modern cellulose-based paper is particularly sensitive to damage from iron gall ink. The problem is less severe on parchment because parchment is treated with lime, which acts as a buffer and has a neutralising effect.
Preservation techniques mainly consist of storing items in favourable climatic conditions, without significant temperature fluctuations and in an environment that is not too humid. Although progress is being made with preservation techniques, it remains difficult to protect paper documents written with iron gall ink from this problem. Sometimes the only way to save the text is to digitise it.
Let us return to our use of iron gall ink on parchment. Here is a recipe for modern copyists and illuminators. There are many recipes, but they can all be traced back to the following ingredients:
1. Tannin
2. Iron sulphate
3. Gum arabic
4. Dissolved in water, sometimes also wine
1. Tannin
Tannin is known as a material that was used for tanning leather. There are various sources of tannin for making ink, but the best known are galls, also known as gall apples. Gall apples or galls are thickened areas on leaves and twigs that can develop for various reasons. When they grow on oak trees, they absorb some of the tannins from the oak bark.
The gall apples on oak trees are caused by the female gall wasp. She pierces a hole in the young oak branches to lay her eggs. The larva that hatches from the egg secretes a substance that forms a small ball around itself. This ball, or gall, protects the larva and is its source of food. When the larva has grown into a wasp, it eats its way out, which is clearly visible from the hole in the gall.
There are many types of galls from various insects, but oak galls are very popular for making ink because of their high tannin content. Aleppo galls, sometimes also called Mecca galls, from Iraq and Turkey are the best, with a tannin content of 50-70%. Incidentally, tannin can also be obtained from the bark of oak or chestnut trees.
2. Iron sulphate
Iron sulphate is a chemical compound of iron and sulphur that has traditionally been used to make ink and black paints. The name vitriol is an outdated term for various sulphates. Green vitriol is iron sulphate and blue vitriol is copper sulphate. Historical inks may therefore contain iron and copper, but in rare cases also zinc. Research shows that this was the case in the writing inks used at the Burgundian court. This has to do with the origin of the vitriol used. At the Burgundian court, copyists used vitriol from the vicinity of the German city of Goslar. This vitriol is known as “Vitriolum Goslariense”.
3. Gum arabic
You can read more about gum arabic in my article on making gum water.
Recipe for making iron gall ink
Requirements:
• Pan
• Demineralised water
• Ground gallnuts
• Iron sulphate/green vitriol
• Filter holder and paper filter
• Wooden spoon
• Gum arabic, preferably powder.
• Bottle(s).
Method:
• Pour 130 ml of demineralised water or a multiple thereof into a pan.
• Add 18 grams of ground gallnuts or a multiple thereof to the water and bring it gently to the boil.
• Then add 350 ml of demineralised water and bring to a gentle boil. Allow to simmer for two hours, stirring continuously. A lot of foam will form, so a larger pan is better for this. Allow to boil until the 350 ml of extra water has evaporated.
• Allow the mixture to cool and filter it through a coffee filter (paper).
• Now add 8 grams of iron sulphate and 7 grams of gum arabic (powder).
• Leave the ink to stand for a few days and then pour it into a bottle.
NB. If necessary, a little more gum arabic can be added. It is a good idea to do some tests to make any necessary changes to the composition. The ink is greyish and watery when you write with it, but oxidation eventually turns it deep black. After a long time in the bottle, sediment may form, so shake well before use.
Some add a preservative. These include cloves or clove oil or natriumbenzoate.
More info on iron gall ink and more recipes: