mixed inks containing elemental carbon and copper

Ingredients

soot, copper, gallnuts

Preparation Steps

Original Recipe Text

The ink composition is compared to a sympathetic ink recipe by Philo of Byzantium (chapter 77[102]): 'The letters are written on a new kausia, or on (human) skin, with crushed gallnuts soaked in water; when the characters dry out, they become invisible; when one grinds flower of copper, like black (ink) in water, and moistens a sponge with it, they become visible whenever one wipes them off with it as with a sponge.' (p. 6). The paper suggests this transition ink used elemental carbon as the primary writing material with added copper-based solutions (p. 8).

Evidence

"Using imaging micro-X-ray fluorescence and infrared reflectography, we discovered that the inks in both documents contain a significant amount of copper in addition to carbon."

Remarks

The study analyzes two famous Greek documents: P 13500 (dated 310 BCE) and P 13501 (dated 284 BCE) (p. 3). The inks are not plain black but appear brownish and have caused corrosive damage to the papyrus substrate (p. 5). The research suggests these inks represent a 'missing link' between early carbon inks and later iron-gall inks, occurring before iron-gall production was fully established (p. 1).