The identification of pigments used on illuminated plates from 'Flora Danica' by Raman microscopy

Six plates in folio format, made from copper engravings, from the collection 'Flora Danica', have been studied by Raman microscopy in order to obtain information about the palette in use in Denmark at the end of the 18th and the beginning of the 19th centuries. The folios examined had been first printed, and subsequently illuminated by hand. The following pigments have been identified: vermilion, red lead, massicot, orpiment, Prussian blue, white lead, chalk, a carbon-based black pigment (probably ivory black or Lamp black) and possibly green earth. No information could be obtained regarding the green pigments, the brilliant yellow pigment or the two orange pigments. No problems of degradation were detected, and the pigments identified are consistent with those found on other European artworks produced at the turn of the 18th century, no synthetic pigments of a later period being identified. Scanning electron microscopy and elemental analysis studies have also been performed in a few cases.