Stabilisation of Iron Gall Ink: Aqueous Treatment with Magnesium Phytate

Corrosive iron ions and acids in iron gall inks lead toenhanced degradation of paper. Several conservation practiceshave been used to stabilise endangered documents inthe past centuries. The most effective aqueous stabilisationmethod developed to date is the so called “Calciumphytate” method. In this contribution we demonstrate thata treatment using magnesium phytate is equally effective,while additionally exhibiting several advantages. Due to thehigher solubility of magnesium phytate compared to calciumphytate, it is not required to add an aqueous solution ofammonia, which poses several health risks.It is also shown that in order to optimise the efficiency oftreatment, the pH of magnesium or calcium phytate solutionshould be adjusted to 5.8-6.0.