The Pigments

What went into the palette

The scribes and painters working in early medieval Irish scriptoria had access to a surprisingly wide range of colours, and the origins of those colours tell a story about trade routes that the vellum itself cannot.

Some materials were local or readily prepared, while others came from further afield. Oak galls and iron-rich water produced the iron gall inks used for ordinary writing. Weld (Reseda luteola), a European plant, yielded yellow. Kermes, a scale insect crushed from Mediterranean oak trees, gave a red. White lead — cerussite — could be prepared from corroded lead sheets, a technique known across the ancient world. Carbon black came from charcoal or lamp soot. These were the workhorses: available, reproducible, relatively cheap.

Then there is lapis lazuli. The most costly blue a scribe could use was ultramarine, ground from lapis lazuli — though pigment analysis shows that the great Insular gospel books, Lindisfarne and Kells among them, relied on indigo for their blues instead. In the early medieval period, lapis lazuli came from a single known source: the Sar-e-Sang mines in what is now Badakhshan, in north-eastern Afghanistan. That stone had to travel overland or by sea through the Islamic world or along Mediterranean networks before it reached the Atlantic edge of Europe. That is why the absence of ultramarine from the great Insular books matters: their long-distance connections are shown instead by imported materials such as orpiment.

Orpiment — arsenic trisulphide — provided an intense yellow-orange that appears in several of the great gospel books. It too was imported; the main ancient sources were Anatolia and the Caucasus. It is worth noting that orpiment is poisonous, something the scribes handling it almost certainly learned by experience. Verdigris, copper acetate, gave green and could be produced more locally by exposing copper to acid vapours, but the quality and hue varied considerably depending on preparation.

Red lead (minium) and vermilion (mercuric sulphide) both appear in manuscript analysis. The word minium, in fact, gave us the term miniature — not through smallness, but through the red pigment used in initial letters and decorative work.

Analysis methods — X-ray fluorescence, Raman spectroscopy, reflectance imaging — have transformed how firmly these identifications can be made, allowing sampling so small as to be essentially non-destructive. Earlier scholarship relied heavily on visual comparison; the chemistry is now considerably more precise. What it confirms is that the palette of even a single manuscript page could be genuinely international: imported orpiment beside locally prepared iron gall and European plant extract, the whole thing bound together with a medium — usually egg white or gum — that left little trace.