The effects of additives on Iranian ink: henna and salt

Among the methods of writing and calligraphy, ink had a special value to Iranian writers and calligraphers: one fourth of the beauty of handwriting was deemed to belong to ink. Unfortunately, excessive use of low quality materials, inaccurate processing, lack of knowledge, or in some cases, jobbery has put valuable works of calligraphy in serious danger of distortion, mold growth, and color bleeding. This study examines the effects of adding henna and salt to the traditional ink. Our aim has been to answer the these two questions: 1) How far does salt and henna extract prevent the growth of mold? 2) Do they enhance the stability of ink on the paper? Method/Research Design: We produced seven samples of black ink, made according to old manuals. We then implemented accelerated aging processes on the samples, using light, mold, and temperature tests. Measurement of the result was carried out by a pH-meter and a colorimeter. Laboratory studies showed that not only does henna have colorific properties but it also prevents the growth of mold in both liquid or dry ink on paper. However, the density of henna affects the germicide property of ink. It is notable that because of the acidic nature of henna, a substantial amount of it (equal to 14 gram) leads to ink pallor and cellulose erosion and destruction. In addition, the minimum amount of salt (equal to 1 gram) helps the stability and durability of ink, as well as prevention of mold. It also controls the erosion and destruction of the cellulose.