History

The earliest use of iron gall ink is hard to establish. The reaction between tannin and iron salt to create a colored product was already known in Antiquity. Gaius Plinius Secundus (23 -79 A.D.) describes an experiment in which he dripped a solution of iron salt on papyrus that had been soaked in a tannin solution. The pale brown papyrus immediately turned black upon contact with the iron salt.

It was not until centuries later that this reaction was deliberately used to produce ink. Carbon ink preceded the use of iron gall ink as the primary writing ink. Various sources refer to the first use of carbon ink in circa 2500 B.C. Carbon inks were made by burning material such as oil, resin or tar. Burning these materials produced soot containing pure carbon and oxidized materials. When properly manufactured, the soot could contain up to 80% carbon particles. This was mixed with water and gum to keep the carbon in suspension. A good quality carbon ink had a blue-black appearance. Such an ink would not discolor with age but could easily smudge with high humidity and was easy to remove from a document.

Aged carbon ink and iron gall ink are sometimes hard to distinguish from one another. Visual examination alone does not provide enough information to identify the ink. Although most iron gall inks turn brown over time, color alone does not indicate an aged iron gall ink. Poor quality carbon inks contain a high proportion of tarry material which also produces a brown color. If the tar content is high and storage conditions poor, the ink might become quite pale. In contrast, some iron gall ink on parchment can, even after centuries, appear deep black and might easily be mistaken for a carbon ink. To distinguish iron gall ink from carbon ink or other inks such as bistre or sepia, a quantitative test for the presence of iron in an ink line is a useful method for determining its identity. However, different inks can still show traces of iron content depending on its method of manufacture and storage.

A very early recipe for iron gall ink can be found in the Encyclopedia of Seven Free Arts by Martianus Capella, who lived in Carthage in the fifth century. In it, Capella describes "Gallarum gummeosque commixtio" as a writing ink. Although the exact date of the transition from carbon ink to iron gall ink is not known, it can safely be stated that by the end of the late Middle Ages iron gall ink was the primary ink. There are examples of manuscripts in which both inks were used. However, iron gall ink had some distinct advantages which led to the eventual displacement carbon ink. Iron gall ink was easier to manufacture, generally did not clog the writing tool, and was hard to remove from the surface on which it was applied - a valued characteristic for official record keeping.

This transition was accelerated by an increasing demand for writing ink, even though writing was a skill of a privileged few. Old household manuals indicate that ink-making was often one of the domestic duties of women. Recipes were also passed from one generation to the next. In contrast to this individualized approach is the strict formulation of ink used in the administration of the seventeenth century trade company "de Verenigde Oost Indische Compagnie" (The Dutch United East Indies Company).

Iron gall ink was used well into the twentieth century, when synthetic dyes were developed. It is interesting to note that an official specification for ink used in official documents of the German government was in use until 1974.