Copper Ink

March 2024.

Collected pure copper from local hardware store and Dad’s basement.

Added copper pieces to glass jar and filled with white vinegar and 1-2 Tablespoons of salt.

Left jar uncovered on a table to soak. Stirred or shook covered 1-2 times a day.

This is poisonous. I took precautions to protect skin and eyes when handling. Kept jar away from pet and child.

Tested at 12 days, 23 days and 30 days, the longer I soaked the more concentrated the blue became. The less I soaked the more crystals appeared on the testing paper.

Noted when this ink interacted with iron (either on paper or inadvertently by touching metal jar cover) it changed to green.

Filtered using coffee filter and bottled ink at Day 23 and Day 30.

I put the oxidized copper pieces back in a jar with remaining sediment and added new vinegar and salt. It continues to produce blue liquid.

I obtained these instructions provided via the brilliant Canadian ink-maker/artist Jason Logan. I did find that I was not able to use found copper pennies. I think this is because after 1980 American pennies contain a fair amount of Zinc, which does not oxidize. I started this experiment in Jan 2024, but the whole conglomeration turned a milky white. In an attempt to salvage the copper, I discarded the liquid and the pennies, and washed the remaining metal to try again, but the liquid remained crystal clear even after 3 months soaking. Started progect over again with new copper in March.