Red inks (I): Mineral pigments

Ink colours

In contrast to black ink, which was used for the body of the text, from very early times the Egyptians used red ink to highlight headings, names and key words, as well as to draw guidelines and the outlining of figures by artists. These practices were continued by the Greeks and Romans. The use of red ink in the Latin world, for example, has originated the Spanish word «rubrica» (from ruber, «red»). This term originally referred to the uses just mentioned, but during the Middle Ages it became specialised to denote the abbreviations of the Latin words scripsit, firmavit and recognovit («written», «signed», «recognised»), which were written in red ink at the end of certain documents, mainly of a legal nature, together with the name of the person or persons involved to certify their authenticity. From this point onwards, it was simply used to denote the personal signature (in Spanish, «firma» or «rúbrica»).

The red inks of the ancient world were mainly made from inorganic materials, such as ochre, a mineral containing iron oxide. Often mixed with clay, it varies in colour from reddish brown to red or yellow. Its use as a pigment is so ancient that it is not exclusive to Homo Sapiens, who used it extensively in rock art. Other sources of red pigment for writing and painting in antiquity included cinnabar (highly toxic due to its mercury content) and minium. The latter, one of the earliest artificial pigments, was manufactured by heating litharge or oxidising lead at high temperatures, which also rendered it dangerous. Unaware of its toxicity, it was one of the favourite colours of the illuminators of medieval Byzantine and Persian codices. The term «miniature» comes from its frequent use in the decoration of manuscripts.