verdigris

Ingredients

copper, vinegar, bronze

Preparation Steps

Original Recipe Text

As described in Abulcasis' Kitab al-Tasrif, verdigris was among the pigments prepared artificially from metal ores. The preparation typically involved the corrosion of copper or bronze when exposed to acidic liquids like vinegar (p. 310, 312). These metallic ores were processed into pigments for decorative arts such as manuscript illumination, painting panels, and frescos (p. 311). The treatise specifically outlines instructions for preparing these ores for both medicinal ointments and artistic colorants (p. 301).

Evidence

"Abulcasis' ninth-century pharmaceutical treatise, Kitab al-Tasrif, for example, contains detailed instructions about how to prepare various metals and metal ores—lead, antimony, iron, bronze, arsenic, mercury, cinnabar, alum, litharge, cadmia, white lead, and marcasite, among others—for inclusion in ointments and eye washes."

Remarks

Copper-based compounds were the most cited materials in the study's survey of arts recipes, appearing in 125 different recipes (p. 301). Verdigris is classified as an inorganic/mineral pigment that was highly ubiquitous in artisanal pursuit, with artificial preparation methods appearing in the ninth-century Kitab al-Tasrif as well as earlier sources like Dioscorides and the Mappae Clavicula (p. 312). The overlap between artistic and medical use is a key finding of the paper, showing that many pigments also served as caustics or solvents (p. 312).