From Oak Galls to the Page: The Return of Iron Gall Ink

Some inks are born in the laboratory. Iron gall ink was born in the woods: from oak galls, from vitriol, from gum arabic. A formula that has crossed the Middle Ages, the Renaissance, and modernity.
Today it returns to the fountain pens of those who want to write with something truly lasting.

Is there still anyone who thinks that inks are all the same?

A little history

As Luca Viti, a long-time partner of Stipula, recalls, iron gall was the benchmark ink from the Middle Ages to around 1950. If of good quality, it has considerable qualities of permanence, resistance, and coloration. This is the reason why «so many ancient manuscripts have reached us still readable». The German government used it for official documents until 1973. It did so «precisely for the permanence of the documents it knew it could ensure».

Even before the Middle Ages, the chemical reaction between tannin and iron salts was known. Pliny the Elder (23-79 AD) describes it in an experiment. He soaks a papyrus impregnated with tannins with iron salts and it turns black instantly. Some centuries later, Marziano Capella (5th century) provided a formula for preparing an ink, which he called "gallarum gummeosque commixtio".

The basic formula had four ingredients: galls, vitriol (iron sulfate), gum arabic, and water. Galls are tannin-rich growths that develop on certain trees, such as the oak. Gum arabic, obtained from acacia, holds the ink together on the paper. To change the characteristics of the ink, beer or wine, vinegar, sugar, honey, or resins were added.

This ink penetrated deeply into the paper and was almost indelible.

For this reason, it was used for centuries also as "security ink": it was difficult to remove from the support, even with abrasion.
According to Luca Viti, a normal ink «is designed to write well today». Iron gall ink, on the other hand, «is designed to write well today and remain readable tomorrow».

One characteristic of the original preparations, freshly made, is the very light color at the time of use. As soon as applied, the ink is almost unreadable and darkens after a couple of seconds, due to oxygen.

Once dry, the color remained black for many years. Then, when all the excess iron had oxidized, it turned towards a more or less dark brown.

Why iron gall ink can be aggressive

The black of the ink is a compound of iron. It forms only with a precise ratio between iron and gallic acid.

Ancient recipes often used too much vitriol, to obtain a darker and more opaque black. The iron that does not bind remains free in the ink. Together with the acid produced by the reaction, it damages the cellulose of the paper (Science in School, no. 6, 2007). The same acidic ink can corrode the metal parts of a pen.

Acidity is not, however, a prerogative of iron gall.
Luca Viti explains that «all fountain pen inks are therefore generally acidic». The degree of acidity depends on the formulations and the pigmentations.

The phenomenon has been studied on paper by the Department of Chemistry and the CSGI of the University of Florence. The study is by Giorgi, Chelazzi, and Baglioni (Proceedings of the V National Congress of IGIIC, Cremona, October 11-13, 2007).
The researchers subjected to accelerated aging, for 30 days, paper with ink prepared as in the historical recipes. The result is a marked drop in the resistance of the cellulose.
The conclusion is that it is necessary to block the excess free iron.
(But the study concerns paper and historical inks, not Stipula ink).

Iron gall ink today

Today it is different: modern inks are much less corrosive and the nibs much more resistant.

Stipula has developed a new formulation of iron gall, in collaboration with the Department of Chemistry of the University of Florence. The balance of the components maintains the typical characteristics of this ink: permanent action on the paper and persistent readability over time.
It is fully compatible with use in fountain pens, starting with the nib.

The ink is produced under the supervision of scientists from the University of Florence. It uses materials of purity higher than 99% and congruent reagents. For Luca Viti it is «a modern ink of superior quality». It offers «the tradition of the permanence of the ink, without the compromises of the preparations of yesteryear».

Viti guarantees that «our iron gall does not cause corrosion in normal use» with stainless steel, titanium, or gold nibs.
Only some pens still have ordinary steel nibs: with these traces of corrosion can appear.
To understand what kind of steel it is, a magnet is enough. If the nib is attracted, Viti explains, «with a high degree of certainty it is not stainless steel».

Stipula iron gall is currently available in black. Discover Stipula iron gall Other colors can be produced on request.
(If you are interested, contact us: we collect preferences to evaluate new productions.)

Maintenance: the essentials

The same quality that makes the stroke permanent on the paper, the impermeability, asks for some attention in use. Three rules are enough to start:

• Use it in a pen that you use regularly. Viti recommends it «in pens that are used regularly»: dried ink is cleaned with time and patience.
• Wash the pen well before filling it and when you change ink. Water and a little dish soap are enough, or a specific detergent like the J. Herbin one.
• Store the bottle in a cool and dark place.

We explain all the details in our article on fountain pen maintenance (in preparation). There will be cleaning, downtime, and what to do if the pen dries out.

So…

Switching to iron gall is not just a matter of aesthetics and pleasure. It is a safe choice for daily use, today as in the past, thanks to oxidation and the permanence of the stroke. All you need is for the pen to be clean and the ink not to remain stationary in the reservoir for long.

As Luca Viti concludes, a clean pen and a stable ink are «the best way to ensure, page after page, the permanence of the writing and the preservation of the writings you wish to pass down».