30/12/2011

"Non-Destructive Characterisation and Dating of Historic Parchment Using Near Infrared Spectroscopy" by Možir et al (2011)


Možir, A.; Strlič, M.; De Bruin, G.; Trafela, T.; Kralj Cigić, I.; Kolar, J.; Deselnicu, V.; "Non-Destructive Characterisation and Dating of Historic Parchment Using Near Infrared Spectroscopy", International Conference on non-destructive investigations and microanalysis for the diagnostics and conservation of cultural and environmental heritage (ART 2011), 13-15 April 2011, Florence, Italy
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Abstract:
Parchment is a complex natural material made from animal skin, which has been used as a writing support and for bookbinding. Due to the historic value of objects made of parchment, understanding of their degradation and their conservation is of high importance to archives, libraries and museums. It was recently shown that lipid content in parchment may have an important influence on collagen degradation, probably via autoxidation. For parchment, a direct link between lipid content and degradation has, however, still not been demonstrated. The goal of this research presented here was to introduce NIR spectroscopy as a new non-destructive spectroscopic method of characterization of proteinaceous historic materials and to examine the relations between lipid content and degradation of parchment, measuring shrinkage temperature.

25/12/2011

"The Bourdichon Nativity: A masterpiece of light and colour" by Burgio et al (2009)

Burgio, L.; Clark, R. J. H.; Hark, R.; "The Bourdichon Nativity: A Masterpiece of light and colour", V&A Conservation Journal 58 (2009) 36-37
URL

16/12/2011

"Microstructural, chemical and isotopic evidence for the origin of late neolithic leather recovered from an ice field in the Swiss Alps" by Spangenberg et al (2010)

Spangenberg, J. E.; Ferrer, M.; Tschudin, P.; Volken, M.; Hafner, A.; “Microstructural, chemical and isotopic evidence for the origin of late neolithic leather recovered from an ice field in the Swiss Alps”, Journal of Archaeological Science 37(8) (2010) 1851-1865
doi:10.1016/j.jas.2010.02.003 (restricted access)

Abstract:
Archaeological leather samples recovered from the ice field at the Schnidejoch Pass (altitude 2756 m amsl) in the western Swiss Alps were studied using optical, chemical molecular and isotopic (δ13C and δ15N of the bulk leather, and compound-specific δ13C analyses of the organic-solvent extracted fatty acids) methods to obtain insight into the origin of the leather and ancient tanning procedures. For comparison, leathers from modern native animals in alpine environment (red deer, goat, sheep, chamois, and calf/cow) were analyzed using the same approach. Optical and electron microscopically comparisons of Schnidejoch and modern leathers showed that the gross structure (pattern of collagen fibrils and intra-fibrils material) of archaeological leather had survived essentially intact for five millennia. The SEM studies of the hairs from the most important archaeological find, a Neolithic leather legging, show a wave structure of the hair cuticle, which is a diagnostic feature for goatskins. The variations of the bulk δ13C and δ15N values, and δ13C values of the main fatty acids are within the range expected for pre-industrial temperate C3 environment. The archaeological leather samples contain a mixture of indigenous (from the animal) and exogenous plant/animal lipids. An important amount of waxy n-alkanes, n-alkan-1-ols and phytosterols (β-sitosterol, sitostanol) in all samples, and abundant biomarker of conifers (nonacosan-10-ol) in the legging leathers clearly indicate that the Neolithic people were active in a subalpine coniferous forest, and that they used an aqueous extract of diverse plant material for tanning leather.

09/12/2011

"3D Micro-XRF for Cultural Heritage Objects: New Analysis Strategies for the Investigation of the Dead Sea Scrolls” by Mantouvalou et al (2011)

Mantouvalou, I.; Wolff, T.; Hahn, O.; Rabin, I.; Lühl, L.; Pagels, M.; Malzer, W.; Kanngiesser, B.; “3D Micro-XRF for Cultural Heritage Objects: New Analysis Strategies for the Investigation of the Dead Sea Scrolls”, Analytical Chemistry 83 (16) (2011) 6308–6315
DOI: 10.1021/ac2011262 (restricted access)

Abstract:
A combination of 3D micro X-ray fluorescence spectroscopy (3D micro-XRF) and micro-XRF was utilized for the investigation of a small collection of highly heterogeneous, partly degraded Dead Sea Scroll parchment samples from known excavation sites. The quantitative combination of the two techniques proves to be suitable for the identification of reliable marker elements which may be used for classification and provenance studies. With 3D micro-XRF, the three-dimensional nature, i.e. the depth-resolved elemental composition as well as density variations, of the samples was investigated and bromine could be identified as a suitable marker element. It is shown through a comparison of quantitative and semi quantitative values for the bromine content derived using both techniques that, for elements which are homogeneously distributed in the sample matrix, quantification with micro-XRF using a one-layer model is feasible. Thus, the possibility for routine provenance studies using portable micro-XRF instrumentation on a vast amount of samples, even on site, is obtained through this work.

02/12/2011

"Conservation of an 18th century targe: stabilization and visual reintegration" by Skogstad (2010)

Hilde Skogstad, "Conservation of an 18th century targe: stabilization and visual reintegration", University of Olso, Institutt for arkeologi, konservering og historie, Master student report (2010)

Introduction:
For historical leather objects which have suffered deterioration in the form of tears, splits and areas of losses, a suitable conservation treatment will often be to add some form of structural support in order to stabilize and prevent further damage. This can be done by inserting repair patches or even a full relining underneath the original material. Although a relevant approach, this form of treatment is not a straightforward one as there is a range of decisions to be made both in terms of repair material, adhesive and the practical, hands- on task of adding the new material without risking or compromising the original. Choices should be based on the condition of the object as well as take into account well known conservation issues like reversibility and minimal intervention. Even if not a first priority, aesthetic considerations will also in most cases be present in the decision making process, maybe more so when the object is historical as opposed to archaeological.
The following case study discusses the conservation of an 18th century Scottish targe from the collections at Leeds Royal Armouries, a project in which several of the above mentioned issues had to be considered in order to stabilize the object and at the same time visually reintegrate areas of damage and losses.