Judith Becker. Piranesi discovered: two albums at the Staatliche Kunsthalle Karlsruhe. Art technological examination and concepts for storage and exhibition. A newly discovered group of 297 drawings by Giovanni Battista Piranesi in two albums was surveyed and evaluated concerning their preservation condition and conservation need in preparation for a future more extensive research project. Most remarkably, the drawings, which show, among other themes, a large number of architectural decorations and designs, show signs of heavy and apparently long-term use as models, which offer unique perspective on Piranesi’s studio practice. A large group of drawings is drawn in red chalk, as well as black chalk and few pen and brush drawings in iron gall ink. Papers vary, some are coarse, others delicate, colors vary in the whitish range, formats are highly irregular due to at least to mounting campaigns evident. Main material features including damages were documented and evaluated in view of future storage and research. Guidelines for handling were given and options for preservation outlined in order to establish a basis for the pending decision making processes. (preperatory study for the German Research Foundation funded research project in cooperation with the Kunsthalle Karlsruhe, 2017–2019)
Dorothea Müller. Paper vertical – concept for the storage of large-format paper objects. A sandwich construction using honeycomb archival board (Klug Conservation) was tested for vertical storage of large paper objects to be sandwiched between the boards additionally secured by magnets and sealed in a large gas-impermeable bag (Marvelseal®) from which air was evacuated to about 200 mbar below atmospheric pressure to ensure even light pressure and stabilize the planarity of the sandwich package.
Marie Kern. Accelerated aging of parchment – developing a climatic-dynamic protocol. The goal was the development of a protocol for the accelerated aging of reconstituted and genuine parchment that does not use extreme temperatures which carry the risk of provoking heat damages in material. The aging test setup was intended to reproduce natural light- and moisture-induced degradation in the presence of oxygen. Test parameters were chosen according to published theories of accelerated aging and common test procedural variants; also taken into account were the material properties of parchment and the mechanics of its chemical and physical degradation. Aging trials were performed on a modern limed goat parchment and pieces of reconstituted parchment (Forstmeyer opaque) prepared for this purpose. Samples underwent accelerated aging for 240 hours in three slightly varied aging cycles: (a) light aging, (b) and (c) combined light aging with dynamic aging at alternating relative humidity in an open system at 30°C and 50°C. The aged samples were evaluated at different structural levels: UV/VIS spectroscopy (visual changes of color), determination of the maximum moisture absorbance capacity (fibre network and interfibrillar spaces, intrafibrillar porosity), climate reflex, fibre examination by light and scanning electron microscopy (fibre condition/fibre surface and subfibriilar elements), determination of the hydrothermal stability (intrafibrillar bonds) and mass spectrometry by Peptide Mass Fingerprinting/MALDI/MS (changes on the molecular level). Aged samples showed a significant color shift and an increased moisture absorption capacity and generally increased climate reflex. A major decrease in shrinkage temperature after accelerated aging suggested advanced fibre degradation. The shift in color some and some findings of the Peptide Mass Fingerprinting suggest degradation at the molecular level. Publication: submitted.
Maria Krämer. Complex! Calcium phytate treatment as a pre-treatment of iron contaminated model papers before bleaching with hydrogen peroxide. Oxidative bleaching with hydrogen peroxide can lead to massive damage of paper including colour reversion when the paper is contaminated with great amounts of iron. The correlation between iron content and damage of the paper substance was studied and a combined calcium phytate-calcium hydrogen carbonate treatment to protect the paper during bleaching and aging was tested. Model papers were prepared from Whatman filter papers that were soaked with iron sulfate solutions of different concentrations. Part of the samples were pre-treated with calcium phytate before all were given an alkaline reserve and bleached in one or three baths of hydrogen peroxide. The papers were artificially aged by light or under changing climatic conditions and examined for optical changes and damage on the paper substance. Paper degradation was examined by the determination of molecular mass and carbonyl group content with gel permeation chromatography with multiple-angle laser light scattering. LA-ICP-MS was conducted on papers that were partially sprayed with lines of iron sulfate to check if the iron ions migrated during the treatment or artificially aging. The higher the iron content in the paper samples, the darker they became over aging and the more they degraded. VIS-spectrometric analysis showed that calcium phytate treated papers darkened less than bleached samples and that bleached samples still darkened less than the references. The references degraded the most during artificially aging, followed by the bleached-only samples and the triple bleached and calcium phytate treated samples. These observations correlated with the decrease of the average molecular mass of the samples: the greatest decrease took place in the references, followed by bleached samples and calcium phytate treated and triple bleached samples. Calcium phytate treated and one time bleached samples changed the least. Changes in carbonyl group content were ambivalent. The line scans showed that the iron was fixed firmly to the paper and did not migrate during treatment or aging. Presentation: M. Krämer, U. Henniges, I. Brückle „Calciumphytatbehandeltes Papier bei der Wasserstoffperoxidbleiche. Ein Versuch mit Musterpapieren“, 23. Fachgespräch der Papierrestauratorinnen und -restauratoren an Archiven, Bibliotheken und Museen in Bonn-Bad Godesberg, Publication: submitted.