Old inks: plant-based inks

Abstract

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles (France). Pigments and dyes can be classified into two broad categories: natural pigments and dyes and those called artificial. These categories are then subdivided into five families. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue) and malachite (green). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue), weld (yellow) and madder (red) compose the family 2 and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the family 3. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. In such purpose, our laboratory in conjunction with the Abbey of Villers-la-Ville has decided to study natural derivatives for inks and focuses in particular on the extraction of pigments from plants