title: On the identification of folium and orchil on illuminated manuscripts.
abstract: The identification of the two purple dyes folium and orchil has rarely been reported in the analysis of painted artworks, especially when analysing illuminated manuscripts. This is not consistent with the fact that ancient literary sources suggested their use as substitutes for the more expensive Tyrian purple dye. By employing non-invasive spectroscopic techniques, the present work demonstrates that these dyes were actually widely used in the production of ancient manuscripts. By employing UV-visible diffuse reflectance spectrophotometry with optic fibres (FORS) and spectrofluorimetry, the abundant identification of both dyes on medieval manuscripts was performed by comparing the spectra recorded on ancient codices with those obtained on accurate replicas of dyed or painted parchment. Moreover, examples are also reported whereby the considered purple dyes were used in mixtures with other colourants. The overall information obtained here allowed us to define new boundaries for the time range in which orchil and folium dyes were used which is wider than previously thought, and to focus on their particular uses in the decoration of books.
authors: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università degli Studi del Piemonte Orientale, viale Teresa Michel, 11, 15121 Alessandria, Italy; Centro Interdisciplinare per lo Studio e la Conservazione dei Beni Culturali (CenISCo), Università degli Studi del Piemonte Orientale, via Manzoni, 8, 13100 Vercelli, Italy. Electronic address: maurizio.aceto@uniupo.it.
authors: Maurizio
authors: M
authors: Aceto
authors: Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Università degli Studi del Piemonte Orientale, viale Teresa Michel, 11, 15121 Alessandria, Italy.
authors: Elisa
authors: E
authors: Calà
authors: Dipartimento di Chimica, Università degli Studi di Torino, via P. Giuria, 7, 10125 Torino, Italy; Nanostructured Interfaces and Surfaces Center of Excellence (NIS), via Giuria, 7, 10125 Torino, Italy.
authors: Angelo
authors: A
authors: Agostino
authors: Dipartimento di Chimica, Università degli Studi di Torino, via P. Giuria, 7, 10125 Torino, Italy.
authors: Gaia
authors: G
authors: Fenoglio
authors: Dipartimento di Chimica, Università degli Studi di Torino, via P. Giuria, 7, 10125 Torino, Italy; Laboratorio analisi scientifiche, Direzione Ricerca e Progetti Cofinanziati, Regione Autonoma Valle d'Aosta, Loc. Lillaz, 7, 11020 Villair de Quart, AO, Italy.
authors: Ambra
authors: A
authors: Idone
authors: Montefiascone Conservation Project, Montefiascone (VT), Italy.
authors: Cheryl
authors: C
authors: Porter
authors: Dipartimento di Chimica, Università degli Studi di Torino, via P. Giuria, 7, 10125 Torino, Italy. Electronic address: monica.gulmini@unito.it.
authors: Monica
authors: M
authors: Gulmini
keywords: FORS; Fluorimetry; Folium; Non-invasive analysis; Orchil