Organic red colorants in Islamic manuscripts (12th-15th c.) produced in al-Andalus, part 1

Abstract

The conservation of Islamic manuscripts in the Fondo Ka'ti created the opportunity to study the organic red colourants applied in five manuscripts, which include a Koran (1198), a theology treatise (14th c.), a book of poems from Al-Sarishi (15th c.), a biography of the Prophet (1468) and manuscript 19 (1485). These dark red colours were characterized using fibre optic reflectance spectroscopy (FORS-VIS), microspectrofluorimetry and infrared spectroscopy (microFTIR). Microspectrofluorimetry detected the presence of a lac dye chromophore in all the manuscripts studied and ascribed it to specific medieval recipes for three of the manuscripts. This was based on the very good matches obtained with our database of paint reconstructions that were prepared according to medieval technical sources; the dark reds found in the Koran compared very well with the recipe ‘to make red ruby from lukk’ from Ibn Bādīs text (11th c.); the brighter reds applied in the book of poems and in the biography of the Prophet, with recipe 113 from the Paduan manuscript (16th c.). MicroFTIR completed the characterization of the paint formulation, identifying the proteinaceous nature of the binding media as well as the fillers. It also showed the presence of oxalate compounds, possibly, resulting from the binding media degradation, a mark of the recent and dramatic history of these books. Finally, these red dyes were successfully compared to lac dye colours previously characterized in 12th-13th c. Portuguese manuscript illuminations. From Mali to Iberia, tracing the rich diversity of a precious heritage legated by medieval Arabic culture.