Seite - 247 - in Europäische Bild- und Buchkultur im 13. Jahrhundert

247 illuminators’ matErials and tEchniquEs The broadening of the palette coincided with developments in theories of co- lour, light and vision underway in Paris and Oxford by mid-century that gave rise to a new discipline. Optics (perspectiva) emerged c. 1260‒1300 as a synthesis of Gre- co-Roman, Arabic and early Christian concepts, and became part of the curriculum in arts faculties across Europe.16 Its proponents revised the Aristotelian linear scale of seven colours and extended it with infinite gradations of hues. Condensed in popular manuals, encyclopaedias, vernacular literature and sermons, optics spread beyond university circles. The perspectivists included members of the mendicant orders who dominated the laity’s spiritual life by mid-century. Optical ideas may have intrigued St Louis and his sister Isabelle, who had Dominican and Franciscan confessors, or the likely patron of the Trinity Apocalypse, Eleanor of Provence, who enjoyed close contacts with the Oxford Franciscans. It is inconceivable that artists, especially those working for learned patrons, remained unaware of the new con- cepts about colour.17 Their images reveal more than awareness – they contributed Stones, Gothic Manuscripts (cit. n. 14), cat. no. I‒13. Stella Panayotova: A Royal Prayer Book. Artistic Collaboration in the Psalter-Hours of Isabelle of France. In: Transactions of the Cambridge Bibliographical Society 16/3 (2018), pp. 309‒343. 16 David Lindberg: Theories of Vision from Al-Kindi to Kepler, Chicago 1976. Katherine Tachau: Vision and Certitude in the Age of Ockham. Leiden 1988. 17 Charles Parkhurst: Roger Bacon on Color. In: The Verbal and the Visual, ed. by Karl-Lud- wig Selig / Elizabeth Sears, New York 1990, pp. 151‒201. Stahl, Picturing Kingship (cit. n. 14), pp. 128‒130. Stella Panayotova: Colour Theory, Optics and Manuscript Illumination. pl. 2a: Psalter of St Louis. Paris, c. 1265–1270. Paris, Bibliothèque nationale de France, lat. 10525, fol. 76r pl. 2b-c: Psalter-Hours of Isabelle of France. Paris, c. 1265–1270. Cambridge, Fitzwilliam Museum, MS 300, fols. 177v (b), 220r (c)