Before applying phytate to the conservation treatment of ink corrosion, it should be proven that the iron gall ink itself is not destroyed by the compound. A useful parameter is the stability constant (K) of the iron (III) phytate complex. Phytate is a natural antioxidant present in seeds. It blocks the production of hydroxyl radicals from hydrogen peroxide by complexation of iron (II) ions, the most important process that leads to the oxidation of cellulose. Ink corrosion was simulated in this study by the accelerated aging of paper treated with an iron gall ink with a composition representative of old ink recipes. The combined treatment with phytate and magnesium bicarbonate increased the half-value period of the bursting index from 6 days to 23 days, and the sole treatment with magnesium bicarbonate increased this period to 15 days; pH values of both treatment sets were similar, confirming the anti-oxidant function of phytate. Future research will focus on the development of a real conservation treatment, based on magnesium phytate. In addition to the anti-oxidant function, treatment with this compound is expected to provide an alkaline reserve to the paper. 8 figures and 37 references