Volume 43, Issue 1-2

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.

Objects made of dyed parchment are relatively rare in libraries and archives. When conservators dye parchment, they are essentially concerned with approximating the colour of the aged original material. Various methods are available today for dyeing parchment and other skin-based materials. This overview describes two methods in detail: staining with pastel chalk and dyeing with leather dye. Dyeing can be carried out before or after the application of an infill, the resulting advantages and disadvantages are briefly described. A look at the basis for decision for or against colour matching aims to motivate further discussion on this topic.

Novel approaches for reconstituted parchment from solely collagenous material are presented. The advantages and disadvantages of this infill technique are named, existing recipes which exclusively use collagenous material are analysed and modified. In a series of experiments, the possibilities to decrease or replace formaldehyde in existing recipes are explored and physical properties are investigated. As a result, two new recipes for reconstituted parchment are developed: the first one with a decreased amount of formaldehyde, the second one with potassium aluminium sulphate instead of formaldehyde. Their haptic and visual qualities are compared.

Ink corrosion on parchment is a phenomenon that, unlike its counterpart on paper, has so far been little researched. The same applies to the options for conservation treatment. In order to provide a guide for conservation practice as well as further research, five water-based treatment methods were examined: calcium phytate with pH 5.3 or 3.0, a 0.5% (w/w) solution type B gelatine, a 1% (w/w) solution of phytic acid at pH 2.2 and calcium phytate in combination with gelatine. These were tested on 70 specimens cut from on piece of buffed vellum and 36 specimens from an early modern deed on parchment that showed signs of ink degradation. After treatment and accelerated ageing, the samples were examined with colorimetry and ATR-FTIR spectroscopy and tested with bathophenanthroline for free iron ions. None of the tested treatment methods achieved a fully reliable inhibition of ink corrosion, but apart from a moisture-catalysed acceleration of degradation reactions, no adverse effects were observed either. Results from ATR-FTIR suggest that oxidation plays a more important role in damage related to ink corrosion of parchment than hydrolysis.

This article focuses on research into two ways of repairing holes found on parchment of Late Antique manuscripts. Their appearance and the reasons for these repairs are analysed and illustrated using the example of the Vienna Dioscorides, a Byzantine manuscript dated to 512. The reconstruction of the manufacturing method of thin Late Antique parchment prepared from lambskins shows clearly that these repairs were an important part of the production process and not subsequent repairs. Conservation of parchment may in some cases have a serious effect on the perception of this important technological evidence.

Parchment manuscripts form an important part of many historic collections. They are often found folded, with some displaying multiple fold patterns resulting from changing uses over their history. Parchment is a potentially fragile medium and folding can increase its susceptibility to damage, as well as hampering access and display. Treatment to address these issues may involve the relaxation of the folded structure, using humidification or a solvent such as propanol, and gentle pressing or stretching. However, this presents a dilemma – an inappropriately folded manuscript may be more prone to damage, but treatments require invasive interventions. This preliminary study has employed infrared spectroscopy and shrinkage temperature measurements to better understand the properties of folded parchment. It demonstrates that physicochemical changes can be detected at the fold and, to a lesser extent, in adjacent areas, compared to the bulk material, and that monitoring these changes allows the impact of different treatment methods to be assessed. This provides a basis for further research into the effect of both the original folding and of potential treatment methods, to inform conservation decisions and help ensure appropriate, effective, and sympathetic outcomes.

This work will give an overview of the scientific approach used for the study of written heritage on parchment. Elemental analysis using X-ray fluorescence (XRF) together with compound-specific analytical methods such as Fourier transform infrared (FTIR) and Raman spectroscopy can be applied in a non-invasive way, without the need for sampling and without inducing changes to the object. Physico-chemical investigations are complemented and further deepened by DNA- and biological analyses for the identification of the biological origin of materials and the identification of microorganisms, insects and viruses that might be present on the object which may add valuable information about its history and conservation state.

Following pilot testing of the effects of alkaline-based nanoparticles on modern parchment, the treatment was extended to historical parchment. This paper describes the application and impact of calcium hydroxide and calcium carbonate nanoparticles dispersed in (i) propan-2-ol and (ii) cyclohexane on a parchment book cover dated 1570. The cover showed signs of damage resulting from contact with iron gall inks and low pH values (∼4–5). Protocols for the damage assessment of collagen in parchment as developed in the IDAP project ( Improved Damage Assessment of Parchment ) were used to evaluate the impact of the conservation treatments on parchment. Preliminary results have shown that the application of calcium-based nanoparticles did not produce any adverse effects on the state of preservation of collagen. In addition, positive outcomes emerged: the pH was re-adjusted to a neutral value, a strengthening and consolidation effect was observed, and the nanoparticles exhibited a protective action upon artificial ageing of the treated parchment.