Technical examination of a fifteenth-century German illuminated manuscripton paper: A case study in the identification of materials

Technical and analytical studies were carried out on a fifteenth-century Ge rman illuminated manuscript, Barlaam and Josephat, in the collections of th e J. Paul Getty Museum. Deterioration of the paper supports has occurred as a result of interaction with the cooper green pigments used extensively fo r illumination. The green pigment was determined by X-ray diffraction to be a variety of basic verdigris and the binding medium, analysed by gas chrom atography-mass spectrometry (GX-MS), was determined to be egg. A dark green glaze was shown to have a glue binder, and is an example of a copper-prote inate complex. An organic red, also in a glue binder, was characterized by thin-layer chromatography and UV/vis spectroscopy as rhubarb, mordanted wit h alum. Rhubarb has not been previously identified as an organic red colora nt in illuminated manuscripts. Vermilion, acurite, lead white and an uniden tified organic yellow were also employed in the decoration. discussion of t he artistic milieu in which the manuscript was produced includes comparison s with well-known manuscripts of the fourteenth and fifteenth centuries suc h as the Strasburg Manuscript and the Gottingen Model Book. The possible op tions for conservation treatment of the embrittled paper support are discus sed.