Take a hot copper bath and call me in the morning.

Cortez writes “Scavenging copper from ancient inks stops archives falling apart: Reports Nature
“Conservators have long known that there is something corrosive about inks from the Middle Ages. Many documents, from sketches by famous artists to political treaties, have fallen apart over time, with holes appearing where the ink used to be. To tackle this problem, Jana Kolar, head of the InkCor project based at the National and University Library of Slovenia in Ljubljana, and her colleagues sought to uncover the exact constituents of the inks. Early analyses had indicated that medieval inks are often full of iron. Free atoms of this metal in the ink react with the air to create oxygen radicals, reactive atoms that break down cellulose, yellowing paper and making it brittle. To the horror of scholars, after hundreds of years this can cause the paper to fall apart.””