Azurite in medieval illuminated manuscripts: a reflection-FTIR study concerning the characterization of binding media

Heritage Science. 2019;7(1):1-9 DOI 10.1186/s40494-019-0262-1

 

Journal Homepage

Journal Title: Heritage Science

ISSN: 2050-7445 (Online)

Publisher: SpringerOpen

LCC Subject Category: Fine Arts | Science: Chemistry: Analytical chemistry

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML, ePUB

 

AUTHORS

Wilfried Vetter (Institute of Science and Technology in Art, Academy of Fine Arts Vienna)
Irene Latini (Institute of Science and Technology in Art, Academy of Fine Arts Vienna)
Manfred Schreiner (Institute of Science and Technology in Art, Academy of Fine Arts Vienna)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 19 weeks

 

Abstract | Full Text

Abstract In illuminated manuscripts, a reliable identification of oxyanion pigments such as azurite by rFTIR is simple, as several combination and overtone bands are strongly enhanced compared to transmission mode. However, the characterization of the used binding media is rather difficult, as the analysis of four medieval manuscripts from the late thirteenth to the fifteenth century (e.g. Cod. slav. 8 in the collection of the Austrian National Library), as well as the earliest known map of Vienna (Albertinischer Plan from 1421, Wien Museum) showed. According to the literature, mainly glair (egg white) and plant gums were applied as binding media for azurite. Moreover, both were used in many cases also as “varnishes” in order to improve optical and mechanical properties of the paint layer. In order to assess the possibilities and to distinguish between proteinaceous and carbohydrate binders, mock-ups with azurite were prepared on parchment support with various quantities of binders. Additionally, some of the specimen were varnished using the binders mentioned above. Furthermore, mock-ups on aluminium foil were prepared to evaluate the influence of the support on the reflection spectra. The results showed that the binding medium content in the mock-ups usually was too low for a reliable determination by rFTIR (except the ones with the highest contents), whereas it was possible to characterize the varnish materials. Only an insignificant influence of the support on the spectra from the mock-ups was observed. However, the spectra obtained from three manuscripts suggested a certain influence of the parchment support, which indicates thinner paint layers.