Browsing by Author "Grayburn, Rosie"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    From Poison Books to “Bibliotoxicology”: Highlighting Hazards in Paper-Based Library Collections
    (Collections: A Journal for Museum and Archives Professionals, 2024-05-31) Grayburn, Rosie; Tedone, Melissa
    The Bibliotoxicology Working Group (“BibTox”) was formed in 2022 as an ad-hoc, international cohort of conservators, cultural heritage scientists, librarians, collection managers, book historians, and health and safety professionals. Sixty members across more than 30 institutions and eight countries in North America, Europe, and Australasia explore reliable identification methodologies for toxic materials in library and archives collections and develop safer practices for managing such collections. This note will discuss the working group’s past activities and future outputs, as well as sharing information about getting involved in the working group.
  • Thumbnail Image
    Item
    Scanning X-ray fluorescence spectroscopy and micro-X-ray absorption near-edge structure analysis as a guiding tool for the conservation treatment of two eighteenth-century Philadelphian portraits
    (X-Ray Spectrometry, 2023-04-02) Porell, Mina; Cushman, Matthew; Fischel, Jason S. T.; Fischel, Matthew H. H.; Sparks, Donald L.; Grayburn, Rosie
    An in-depth technical examination and conservation treatment of paintings by William Williams (Bristol 1727–1791 Bristol) has shed light on the artist's materials and technique. This investigation centered primarily on Williams's two 1766 portraits of William and David Hall. The paintings are considered the earliest life-sized, full-length portraits executed in the Philadelphia area. The analysis of the artist's palette indicated deliberate choices in the use of orpiment (As2S3). The mineral's tendency to oxidize to colorless and water-soluble arsenic oxides likely caused color changes and degraded organic binder in the orpiment-rich areas. μ-XANES revealed orpiment photodegradation to arsenate species at the paint surface, with migration to the ground layers. Just below the paint surface, arsenic remains bound primarily as arsenite, with some associated with sulfur as orpiment. This As distribution suggests that the paint is liable to further degradation by photooxidation and use of moisture would be detrimental. Given this treatment-critical degradation phenomenon, it was important to identify all arsenic-containing areas of both portraits. Scanning XRF allowed rapid and accurate collection of maps from both portraits. Elemental maps of arsenic identified the orpiment-rich areas of the painting, which would be susceptible to further degradation upon exposure to water during treatment. An aqueous adhesive was necessary to consolidate the cupped paint of the glue-paste lined paintings. The arsenic maps guided the use of two different consolidants–BEVA 371 for the water-sensitive orpiment-rich paint and sturgeon glue for all other areas, striking a compromise between esthetic improvement and long term preservation.