Substantial-Pie1758 t1_jegl9h7 wrote on March 31, 2023 at 9:28 PM Reply to comment by Kwiercyski in When a nail is hammered into an oak tree, it sends a blue vein up the wood. by Kwiercyski People in the past used a similar reaction to make iron gall ink. They would take the tannins from oak galls and mix with iron to make black ink. Permalink Parent 2
Substantial-Pie1758 t1_jegl9h7 wrote
Reply to comment by Kwiercyski in When a nail is hammered into an oak tree, it sends a blue vein up the wood. by Kwiercyski
People in the past used a similar reaction to make iron gall ink. They would take the tannins from oak galls and mix with iron to make black ink.