These kinds of pigments are described by Pliny, Hist. Nat. XXXV. 44 and 46; and by Vitruvius, VII. xiv. Eraclius in his work on technique, De artibus Romanorum, calls them colores infectivi, "dyed colours," an accurately expressive phrase.
One method, occasionally used for the cheaper class of manuscripts, was to paint on to the vellum with white lead, and then to colour it by repeated application of a brush dipped in the thin dye-pigment. Many of the colours mentioned below belong to this class.
| Terra verde. |
Terra verde.Green pigments. A fine soft green much used in early manuscripts is a natural earthy pigment called terra verde or green Verona earth. This needs little preparation, except washing, and is of the most durable kind; it is a kind of ochre, coloured, not with iron, but by the natural presence of copper.
| Verdigris green. |
Verdigris green.A much more brilliant green pigment was made of verdigris (verderame) or carbonate of copper, produced very easily by moistening metallic copper with vinegar or by exposing it to the fumes of acetic acid in a closed earthen vessel; see Theophilus, I. 37.
Verdigris green was much used by manuscript illuminators, especially during the fifteenth century, when a very unpleasant harsh and gaudy green appears to have been popular. When softened by an admixture of white pigment, verdigris gives a pleasanter and softer colour.
| Chrysocolla. |
Chrysocolla.A native carbonate of copper, which was called by the Romans chrysocolla[[272]], was also used for mediaeval manuscripts. It is, however, harsh in tint if not tempered with white. Both the last-named pigments were specially used with yoke of egg as a medium.
Prasinum, a vegetable green made by staining powdered chalk with the green of the leek, was sometimes used.