“…iron gall ink on parchment”

Submitted by Sammy Smith (sammy@thesga.org)

Georgia’s official copy of the Declaration of Independence was made with iron gall ink on parchment. It was made in response to a Congressional order made on January 18th, 1777.

So what does this mean: “iron gall ink on parchment?”

Parchment is a pretty common term. Of course, there is parchment paper, which you may have seen and used, but real parchment is made from animal skin (hide). Unlike leather, the skin is not tanned, but instead is treated with lime. Fine quality parchment is called vellum. The Wikipedia has a detailed entry on parchment.

How about iron gall ink? It’s not common these days! Of course, ink is becoming less common the more we use keyboards and make PDFs that remain forever digital!

Iron gall ink is also called iron gall nut ink or oak gall ink. The name for this ink comes from the two main components, iron and galls.

Inks, of course, are fluids containing pigments and/or dyes.

Iron is easy—it’s a metal, common to nails and other everyday items.

So, what are galls? Galls are round swellings on plants that are abnormal growths that the plant makes in response to damage, often made by insects. Oak marble galls are caused by gall wasps, which in this case lay their eggs in tender buds of particular species of oaks. The oak reacts by growing a lot of tissue to encapsulate this invasion. These galls are usually very round, hence the term “marble.”

Iron gall ink was the standard writing and drawing liquid used for hundreds of years across Europe, and beyond. Iron gall ink was used by Leonardo Da Vinci, and for the Dead Sea Scrolls; Van Gogh used it, and so did Bach. Indeed, it was the standard for public documents in the Colonies at the time of the Revolution.

Iron gall ink was preferred because of its longevity. The ink would bond with the parchment, rather than merely sit on the surface, like some other pigmented liquids. Also, the ink reacts to oxygen and becomes darker over the next few days after it is used.

To make iron gall ink, you start with two different liquids. The chemistry of iron gall ink is rather complicated, and best left to experts (for example, here). Briefly, one liquid is an iron solution, which can even be made by putting carpentry nails in vinegar. The other is an oak extraction, commonly made from oak marble galls, which have the high levels of tannin that are critical to the chemistry of the ink. When mixed, iron ions reacted with the tannic acid to make the ink (mostly). Other chemicals are added to make the liquid less acidic and more stable. Gum arabic has been commonly added to iron gall ink preparations to make the pigments stay in solution. It comes from the sap of acacia trees, native to northern Africa.

Are you surprised that it took two different trees to make the ink used for the documents of Colonial America? What else do you find interesting about “iron gall ink on parchment?”

Online materials

Downloadable PDF of the Federal archives copy of the Declaration of Independence….

Information on the Georgia copy of the Declaration of Independence in the State Archives….

To make iron gall ink….