The Development of a New Conservation Treatment for Ink Corrosion, Based on the Natural Anti-oxidant Phytate

Ink corrosion, the degradation of the substrate caused by the corrosive action of irongall inks, is a difficult rcstorati~~e problem encountered with manuscripts and pen drawings made on paper or parchment. Different causes have been suggested for the degradative process. Irongall inks usually contain acid: pH values range fro~n 1.0 3.1'. Acid catalyses the hydrolysis of cellulose in paper2. In general, deacidification slows down ink corrosion3. During accelerated ageing however, it failed to protect the paper against the recurrence of new acidity, as was shown by Hey4. Therefore, acidity can not be the only cause of ink corrosion. Simulating tests of ink corrosion by accelerated ageing of different types of paper treated with irongall ink showed that the lignin-free paper degraded faster than the lignin-containing paper, even in the presence of acid alum sizing in the latter 5'6. Lignin will act as an anti-oxidant because it is oxidised faster than cellulose and forms stable radicals7. Therefore, this observation is indicative of the oxidative character of the process.