The ink used to write the U.S. Constitution and Declaration, iron gall ink, is associated with which historical writing medium?

• A. Iron gall ink
• B. Sepia ink
• C. Carbon ink
• D. Charcoal ink

Answer: (A)

Iron gall ink is historically paired with parchment as the standard combination for important legal documents. This ink is made by mixing tannin sources from gall nuts with iron salts, producing a dark, durable compound that binds well to the surface of parchment (animal skin prepared for writing). The U.S. Constitution and Declaration were written on parchment, and the iron gall ink used with that surface provided long-lasting legibility despite centuries of handling and storage. Other inks, like sepia from cuttlefish, carbon-based inks, or charcoal inks, do not share the same long-term durability on parchment, which is why the iron gall-on-parchment pairing is the one most strongly associated with these historic documents.