"Non-destructive spectroscopic characterization of parchment documents" by Bicchieri et al (2011)

Bicchieri, M.; Monti, M.; Piantanida, G.; Pinzari, F.; Sodo, A.; “Non-destructive spectroscopic characterization of parchment documents”, Vibrational Spectroscopy 55(2) (2011) 267-272

doi:10.1016/j.vibspec.2010.12.006 (restricted access)

Abstract:

Membranaceous substrates – widely found in library heritage– are truly challenging, due to the variety of manufacturing traditions, the intrinsic variability of the animal's skin and the different degradation patterns affecting documents along ageing. Moreover, when dealing with unique and delicate objects as cultural heritage specimens, sampling is never recommended and often explicitly forbidden. Aim of the research presented in this work is to achieve correct protocols for unambiguous characterization of the document's materials chemical structure and of the possible surface treatments.

Experimental results allow us to evidence that the chosen non-destructive techniques (Raman, ATR-FTIR and SEM/EDS) provide a good differentiation between parchment manufacturing procedures, western with lime and eastern with enzymatic treatment. Incrustations of salts on the surface as well as superficial treatment with tannin can be clearly detected. Origin of tannin – from the surface or in ink – can also be distinguished.

Choice of the better technique is sample-dependent, since preparation methods, degradation, presence of incrustations, amount of tannin, dehairing method can differently affect the spectral features. For instance, Raman appears to be the most effective molecular technique on western parchment, whereas ATR-FTIR allows distinguishing the enzymatic dehairing procedure from the chemical one.

Qur'an case, Nasrid period, Spain, 15th century, The Met Museum of Art

"Qur'an case [Spain] (04.3.458)". In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/works-of-art/04.3.458 (October 2010)"

Leather embroidered with gilt-silver wire.

"L'évolution des différentes méthodes de tannage" par Thuau (1921)

Thuau, U.; "L'évolution des différentes méthodes de tannage", Le Cuir 10(4) (1921) 80-84
URL

"Skin tight" by McHugh (2011)

McHugh, S.; "Skin tight", The ethnographic conservation newsletter of the Working Group on Ethnographic Materials of the ICOM Committee for Conservation 32 (2011) 8-11
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Introduction:

In 2009 an unusual and complex treatment was carried out at the National Gallery of Australia on a skin covered Janiform (two faced) mask from Nigeria. Now an important part of the National Gallery’s small African collection, the Janiform mask was already in poor condition when it was acquired in 1974. As suggested by the name, it has two faces back to back, thought to be male and female, with raised designs imitating local scarification practices. It is constructed from what is believed to be antelope skin, stretched over a two part hard wood structure, and a loss to one side of the wood had caused movement and subsequent tears and losses to the skin. Testing was carried out to determine the most effective methods and materials for the necessary repairs, based on a literature search for treatments on similar materials. A brief mention in one paper of natural skin condoms caught the conservators’ attention and these eventually turned out to be the most useful material tested and key to the success of the treatment that followed.

"Dynamic mechanical analysis (DMA) of new and historical parchments and leathers.." by Cucos et al (2011)

Cucos, A.; Budrugeac, P.; Miu, L.; Mitrea, S; Sbarcea, G.; "Dynamic mechanical analysis (DMA) of new and historical parchments and leathers: correlations with DSC and XRD", Thermochimica Acta 516, Issues 1-2 (2011) 19-28
doi:10.1016/j.tca.2011.01.006 (restricted access)

Abstract:

A sort of pure collagen, 22 sorts of new parchments, 35 sorts of old (14th–19th centuries) parchments, 19 sorts of new vegetable tanned leathers and 31 sorts of old (15th–19th centuries) leathers were investigated by DMA technique in tensile mode from room temperature to 260 °C. The obtained results were correlated with those determined by DSC measurements performed in N₂ flow in the same temperature range and by XRD. It was pointed out that all collagen-based materials contain a “crystalline” region exhibiting a phase transition (“melting”) in the temperature range 210–260 °C, which is characterized by an endothermic peak in the DSC curve and an abrupt decrease of storage modulus in DMA. Differences in the parameters of this phase transition, related to various deterioration levels, were put in evidence and discussed.