Word of the day: iron gall ink

The word of the day is iron gall ink:

At its simplest, iron gall ink is made from four main ingredients:

• gall nuts (source of tannins),
• iron sulfate (source of iron),
• water (solvent),
• gum arabic (binder).

(http://travelingscriptorium.library.yale.edu/2013/03/21/iron-gall-ink/)

"Rubenstein's Magna Carta, written in iron gall ink on sheepskin parchment, is on long-term loan to the National Archives."

 - Laura Demanski, "Chartered philanthropy: As the historic document turns 800, David M. Rubenstein, JD '73, reflects on preserving a Magna Carta in the United States", Fall 2015 The University of Chicago Magazine (http://mag.uchicago.edu/law-policy-society/chartered-philanthropy)