A combined approach, using molecular and microscopic techniques, was used to identify the microbiota associated with the Archimedes Palimpsest, an unusual parchment manuscript. SEM analyses revealed the microbial damage to the collagen fibers and the presence of characteristic cell chains typical of filamentous bacteria and fungal spores. Molecular analysis confirmed a homogeneous bacterial community colonizing the manuscript. The phyla Proteobacteria and Actinobacteria were associated with this ancient parchment; the sequences were most related to uncultured clones detected in the human skin microbiome and in ephitelium, and to cultivated species of the genera Acinetobacter and Nocardiopsis. Nevertheless, a great variation was observed among the different sampled areas indicating fungal diversity. Blumeria spp. dominated in the healthy areas of the parchment while degraded areas showed disparate fungal communities, with dominant members of the genera Mucor and Cladosporium. In addition, the quantification of the β-actin gene by real-time PCR analyses (qPCR) revealed a higher fungal abundance on degraded areas than on the healthy ones.

The 6th century Codex Sinopensis or Sinope Gospels (Paris, Bibliothèque nationale de France) is one of the most precious purple codices that survive from the Late Antique period. Together with the Vienna Genesis (Wien, Österreichische Nationalbibliothek) and the Rossano Gospels (Rossano Calabro, Museo Diocesano), it has an unusually rich decorative apparatus with scenes representing biblical episodes. It can be, therefore, considered one of the most important preserved artistic productions of the early medieval era. The manuscript has been subjected to a non-invasive diagnostic campaign to evaluate the quality of the colourants used in its decoration, to understand how the parchment was coloured, and to carry out a comparison with the Vienna Genesis and the Rossano Gospels. The techniques used were UV-visible diffuse reflectance spectrophotometry with optical fibres (FORS), X-ray fluorescence spectrometry (XRF), spectrofluorimetry, and optical microscopy. Analyses highlighted the presence of ultramarine blue, which, besides the use of pure gold for the ink and paint, certifies the high value of the manuscript. In addition, this must be seen as one of the earliest examples of its use in paintings. The purple colour of the parchment was identified as orchil, a dye extracted from lichens, similar to the results of analytical investigations carried out on other purple codices, and not the expected Tyrian purple dye.

The investigation and conservation of the Vienna Genesis, a Late Antique manuscript on purple parchment, included the study of parchment production and purple dyeing in the sixth century. The process of parchment making and of purple dyeing was recreated and compared with the Vienna Genesis and other manuscripts from the sixth and eighth centuries. Parchment made from the hides of young lambs and dyed with orchil resembled the folios of the Vienna Genesis. The results of material analysis and the study of parchment technology influenced decisions for the conservation and storage of the manuscript. Fragile areas of ink and parchment were stabilised with strips of adhesive coated Japanese tissue paper. The single folios are stored in folders of Japanese paper and museum matboard within a sink mat.

Early in his career as a rare book conservator Christopher Clarkson worked at the Walters Art Museum in Baltimore, Maryland, from February 1977 to August 1979. Hired by the Curator of Manuscripts and Rare Books, Dr. Lilian M.C. Randall, with a grant from the National Endowment for the Humanities, Clarkson conducted a condition survey of the western European manuscripts and wrote detailed descriptions of their structure and bindings for the first comprehensive catalogue to be published of the collection. Clarkson provided training for Walters staff in the handling and display of early books and, with Randall's support, drafted a lengthy monograph on the subject that included instructions on the fabrication of Plexiglas® book cradles. As Clarkson's time was limited, he was unable to undertake the specialized treatment of manuscripts with broken textblocks and bindings. Recognizing the complex problems of thickly applied media on flexible parchment supports, Clarkson made a significant contribution to the preservation of the Walters collection by recommending important changes to existing protocols, established in the late 1960s, for the consolidation of flaking paint in the manuscripts. The experience that Clarkson had at the Walters was significant, as it shaped his thinking about the role of the conservator in studying and caring for early books and in establishing model preservation programmes for special collections in research libraries as well as museums.