Band 44, Heft 1

This research project examines the effects of X-rays on cellulose and some moulds frequently found on paper. The aim was to identify applications for X-ray irradiation that can be used as a disinfection method for archival material. The question was if X-rays are suitable as an alternative to gamma radiation and if they are less harmful. For this purpose, the minimum X-ray dose required to reduce the microbial count to a harmless level was determined. The material-altering effect was examined on samples treated with X-rays and gamma radiation. Spectrophotometric measurements showed that there is no noticeable colour change with either type of radiation. The determination of the molecular weight distribution, in turn, showed that the molar mass of the cellulose is considerably reduced with both treatment methods. Using mechanical tests, however, it could be demonstrated that this has no significant influence on the tensile strength. The examination of the oxidation behaviour also showed no significant difference between the differently treated samples. The studies demonstrated that both methods have an almost identical effect on cellulose. Thus, X-ray treatment is primarily a supplement to the known disinfection methods and is particularly suitable for objects that would not withstand treatment with alcohol.

A batch of paper manuscripts of the Tang Dynasty unearthed from the Western Regions represents one of the most important special collections at the Museum of Renmin University of China. These paper manuscripts are a unique source for studying history, religion, paleography, and culture. Due to their age and the detrimental storage environment, most manuscripts were severely damaged and incomplete and needed conservation treatment. One of these manuscripts dated to the 5th year of the Zhenyuan period (789 C.E.) was distorted and it was not possible to identify its content; it also posed serious challenges for handling. This paper proposes method for preserving this manuscript. Soiling was removed using dry-cleaning methods, followed by unfolding the folds with tweezers, mending losses and lining. After conservation measures, the surface of the manuscript was flat, and the handwriting was recognizable. For long-term storage and utilization, the manuscript was encapsulated in paper and stored in a self-made paper folder. This paper aims to contribute to research on a safe and reliable method for preserving severely damaged and distorted manuscripts.

Clay minerals possess several properties such as ion exchange capability, alkaline pH, adsorptive, swelling, and plastic behaviour, most of which are governed by their interactions with water. They have the capacity to interact with soluble molecules, which is particularly interesting for art conservation treatments. For all these reasons clays deserve to be considered for green and sustainable paper conservation interventions. In this work two phyllosilicates with different properties, namely montmorillonite and sepiolite, were investigated for the removal of tidelines on artificially aged paper samples. Water exchange, cleaning efficiency, and pH were evaluated comparing the clays to gellan gum, a benchmark cleaning hydrogel. A pouch made with regenerated cellulose was used to avoid direct contact of the minerals with the paper. The water sorption capacity of the clays combined with the specific permeability of the cellulosic membrane allowed for a homogeneous and easy to control cleaning. The formation of new tidelines, an inherent risk to any local conservation treatment of paper, was avoided. As an example, sepiolite was used for the local cleaning of a paper-based artwork’s multiple tidelines.

A small framed display panel holds a selection of paper and media common in works on paper plus a set of Blue Wool Standards. The selection of materials and design of the panel including two types of glazing are presented, and the purpose of the panel as a tool for explaining the effects of light on materials is discussed. At the centre of the panel are watercolour samples prepared using primary colours in mixed washes that illustrate hue shift resulting from selective fading of one colourant.