A combination of FTIR, normal Raman, SERS, Py-GC/MS and XRF was used to analyze commercial bistre samples to determine specific biomarkers that will allow for a rapid identification of the pigment in works of art. The results of the XRF analysis showed that potassium, calcium and iron are the main elements present. Characteristic bands belonging to phenolic components of lignin were observed in the FTIR spectra. The SERS analysis provided a fingerprint that may originate in the polymerization of the phenolic components catalyzed by the presence of the nanostructured silver surface under alkaline conditions. The Py-GC/MS analysis revealed the presence of lignin and cellulose biomarkers and a series of polycyclic aromatic hydrocarbons. The similarities observed between the commercial samples studied suggest that both originate in the same raw material, hardwood. The results demonstrate the potential of the multi-technique approach used for the characterization of this complex black-brown pigment.

A folio fragment attributed to the Fatimid period in Egypt was found to bear tufts of white crystals associated with the orange-brown and yellow paints. Raman spectroscopy identified a mixture of arsenic sulfide-based pigments in the orange-brown and yellow areas, along with vermilion in the outlines of the figures. X-ray microdiffraction, Raman spectroscopy, and energy-dispersive X-ray spectrometry identified the white crystals as hörnesite [Mg 3 (AsO 4) 2 •8H 2 O]. Synthesis of this compound at ambient temperature and elevated relative humidity over a period of 3 years, on paper painted with arsenic sulfide pigments and treated with magnesium carbonate, suggests the possibility that a magnesium-based deacidification treatment may have contributed to the formation of this phase on the folio fragment. This work highlights the potential damage that may be sustained by arsenic sulfide-based media through exposure to deacidifying suspensions such as the ones often used in the past to treat works of art on paper and historic documents.

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In the spring of 2017, the Islamic Art Department, within The Metropolitan Museum of Art (TMMA), acquired an Islamic prayer book, the Dalāʾil al-Khayrāt by Muḥammad bin Sulaymān al-Jazūlī. This paper discusses the findings of a technical study undertaken in the museum’s Sherman Fairchild Center for the Conservation of Works of Art on Paper, focusing on the materials and techniques of one manuscript acquisition specifically, MMA 2017.301. The nature, properties, and characteristics of the text block paper, fiber and pigment identification, chemical compositions, condition assessment, and inherent deterioration mechanisms within the palette are described. The colophon at the end of the manuscript mentions a patron, Sīdī Aḥmad b. Dirham al-Mālikī and identifies its calligrapher as Muḥammad bin Aḥmad bin ʿAbd Al-Raḥmān al-Riyāḥī and confirms its creation date as AH 1035/1625–1626 AD.1