Investigating the Impact of Absinthium Additive on Stabilization of Color of Iron-Gall Ink

Iron-gall ink is one of the varieties of inks used in the past that consists of four main components of gall nut, vitriol, gum arabic and water and due to chemical instability changes color over time. The present study tried to investigate the impact of the extract of absinthium, as well as the ratio of gall to the alum used in the manufacture of ink on stabilization of the color of iron-gall ink based on old references and through laboratory studies. In this study, after making two types of black ink using old sources, the samples were exposed to light and temperature-humidity aging and after examination by using acidity and colorimetric tests, it was determined that adding extracts of Artemisia absinthium to iron-gall ink can stabilize its color, and the ratio of gall to alum is also an important factor in this sustainability.