Hacker News with Generative AI: Ink

Iron Gall Ink (wikipedia.org)
**Iron gall ink** (also known as **common ink**, **standard ink**, **oak gall ink** or **iron gall nut ink**) is a purple-black or brown-black [ink](/wiki/Ink "Ink") made from [iron](/wiki/Iron "Iron") salts and [tannic acids](/wiki/Tannic_acid "Tannic acid") from vegetable sources.
Making iron gall ink from oak galls (gitlab.io)