Série Encyclopédique Glucq des leçons de choses illustrées, Imagerie d'Épinal n.º 3817, Cuirs & Tannerie

“Skin-Covered Masks from the Cross River Region of Nigeria and Cameroon at the National Museum of African Art: A Technical Study” by Owczarek (2014)

Owczarek, Nina, “Skin-Covered Masks from the Cross River Region of Nigeria and Cameroon at the National Museum of African Art: A Technical Study”, Journal of the American Institute for Conservation 53(3) (2014) pp. 182–197.

DOI:10.1179/1945233014Y.0000000025 (Taylor & Francis Online, restricted access)

Abstract:

Nineteen skin-covered masks from the Cross River region of Nigeria and Cameroon were studied at the National Museum of African Art. The construction of the masks are documented and compared against existing field literature. Results of analyses of the wood, skin, and surface applications are included, as well as detail images of construction features. In addition to visual examination, x-radiography, thin section, deoxyribonucleic acid, portable x-ray fluorescence, x-ray diffraction, and Fourier transform infrared analysis techniques were employed in the examination. For the most part, this study showed the skin-covered masks in the NMAfA collection support the basics of the field literature descriptions while also illustrating a wider variety in techniques and materials.

Crest mask, Cross River region of Nigeria, 19th-20th century, Smithsonian National Museum of African Art

“Saving our skins: long-term care of masks from the Cross River Region” by Julien (2000)

Julien, Sophie, “Saving our skins: long-term care of masks from the Cross River Region”, Journal of Museum Ethnography 12 (2000) pp. 115–124.
URL (JSTOR, restricted access)

Abstract:
This paper gives a conservation perspective on collecting and conserving ethnographic material in the museum context, using the example of the Horniman Museum's collection of skin-covered masks from the Cross River Area of Nigeria.

“Nanomaterials for the cleaning and pH adjustment of vegetable-tanned leather” by Baglioni et al (2016)

Baglioni, Michele; Bartoletti, Angelica; Bozec, Laurent; Chelazzi, David; Giorgi, Rodorico; Odlyha, Marianne; et al., “Nanomaterials for the cleaning and pH adjustment of vegetable-tanned leather”, Applied Physics A 122(2) (2016) pp. 1–11.

DOI:10.1007/s00339-015-9553-x (SpringerLink, restricted access)

Abstract:

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on aging and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable-tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study, the cleaning of historical leather samples was optimized by confining an oil-in-water nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using scanning electron microscopy, controlled environment dynamic mechanical analysis, and infrared spectroscopy. The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

“The Chester leather industry, 1558-1625” by Woodward (1967)

Woodward, D. M., “The Chester leather industry, 1558-1625”, Transactions of the Historical Society of Lancashire and Cheshire 119 (1967) pp. 65–111.
PDF (The Historic Society of Lancashire & Cheshire)

La dorure sur cuir: reliure, ciselure et gaufrure en Allemagne par Stockbauer et Maul (1888)

Stockbauer, Jacob; Maul, Johannes; La dorure sur cuir: reliure, ciselure et gaufrure en Allemagne, 2 vol., Paris, B. Rouveyre (1888).

URL (Gallica)

“Detection of COL III in parchment by amino acid analysis” by Sommer and Larsen (2016)

Sommer, Dorte V. P.; Larsen, René; “Detection of COL III in parchment by amino acid analysis”, Amino Acids 48 (1) (2016) pp. 169–181.

DOI:10.1007/s00726-015-2074-2 (SpringerLink,restricted access)

Abstract:

Cultural heritage parchments made from the reticular dermis of animals have been subject to studies of deterioration and conservation by amino acid analysis. The reticular dermis contains a varying mixture of collagen I and III (COL I and III). When dealing with the results of the amino acid analyses, till now the COL III content has not been taken into account. Based on the available amino acid sequences, we present a method for determining the amount of COL III in the reticular dermis of new and historical parchments calculated from the ratio of Ile/Val. We find COL III contents between 7 and 32 % in new parchments and between 0.2 and 40 % in the historical parchments. This is consistent with results in the literature. The varying content of COL III has a significant influence on the uncertainty of the amino acid analysis. Although we have not found a simple correlation between the COL III content and the degree of deterioration, our results show that this question must be taken into consideration in future studies of the chemical and physical deterioration of parchment measured by amino acid analysis and other analytical methods.

“Proteins in Art, Archaeology, and Paleontology: from detection to identification” by Dallongeville et al (2016)

Dallongeville, Sophie; Garnier, Nicolas; Rolando, Christian; Tokarski, Caroline, “Proteins in Art, Archaeology, and Paleontology: from detection to identification”, Chemical Reviews 116(1) (2016) pp. 2–79.

DOI:10.1021/acs.chemrev.5b00037 (ACS Publications, restricted access)

“Quantifying degradation of collagen in ancient manuscripts: the case of the Dead Sea Temple Scroll” by Schütz et al (2013)

Schütz, R.; Bertinetti, L.; Rabin, I.; Fratzl, P.; Masic, A., “Quantifying degradation of collagen in ancient manuscripts: the case of the Dead Sea Temple Scroll”, Analyst 138(19) (2013) pp. 5594–5599.

DOI:10.1039/C3AN00609C (Royal Society of Chemistry, open access)

Abstract:

Since their discovery in the late 1940s, the Dead Sea Scrolls, some 900 ancient Jewish texts, have never stopped attracting the attention of scholars and the broad public alike, because they were created towards the end of the Second Temple period and the “time of Christ”. Most of the work on them has been dedicated to the information contained in the scrolls' text, leaving physical aspects of the writing materials unexamined. They are, however, crucial for both historical insight and preservation of the scrolls. Although scientific analysis requires handling, it is essential to establish the state of degradation of these valued documents. Polarized Raman Spectroscopy (PRS) is a powerful tool for obtaining information on both the composition and the level of disorder of molecular units. In this study, we developed a non-invasive and non-destructive methodology that allows a quantification of the disorder (that can be related to the degradation) of protein molecular units in collagen fibers. Not restricted to collagen, this method can be applied also to other protein-based fibrous materials such as ancient silk, wool or hair. We used PRS to quantify the degradation of the collagen fibers in a number of fragments of the Temple Scroll (11Q19a). We found that collagen fibers degrade heterogeneously, with the ones on the surface more degraded than those in the core.

"Parchment production in the first millennium BC at Seglamen, Northern Ethiopia" by Phillipson (2013)

Phillipson, Laurel; "Parchment production in the first millennium BC at Seglamen, Northern Ethiopia", African Archaeological Review 30(3) (2013) 285–303.
doi:10.1007/s10437-013-9139-y (SpringerLink, restricted access)

Abstract:

Traditional Ethiopian and European processes of parchment manufacture and their associated tools are described and compared with artefacts recovered from an important pre-Aksumite site at Seglamen, in the highlands of northern Ethiopia. Many close similarities of tools used at Seglamen in both the earlier and later phases of the pre-Aksumite, from about 800 BC, to implements used by present-day Ethiopian scribes attest to the systematic production of parchment at Seglamen and to cultural continuity over a period of almost three millennia.

"Curtimento de peles" por Leite (1912)

 

Leite, Manuel da Silva; "Curtimento de peles", Ilustração Portuguesa 350 (1912) 601-604.

PDF (Hemeroteca Digital de Lisboa)

Classification of finishing tools in Greek bookbinding by Sarris (2010)

Sarris, Nikolas; Classification of finishing tools in Greek bookbinding: establishing links from the Library of St Catherine's Monastery, Sinai, Egypt. PhD thesis, University of the Arts London (2010).

URL (UAL Repository)

Abstract:
The thesis examines the decoration of Greek bookbinding, through the study of the leather-covered bindings from the monastery of Saint Catherine in Sinai, Egypt.
The manuscript collection is remarkable for the variety of binding styles that represent mainly Greek but also other bookbinding traditions, including Georgian. Syrian and Eastern European. The examination of the decorative motifs tooled on the leather covered bindings aims to identify the style and characteristics of bookbinding at the monastery. Moreover, links between and evidence for specific bindings and the manuscripts they contain are established by grouping them and relating them to specific binders and bookbinding workshops. The workshops of the monastery are examined in parallel with groups of bindings that were imported into the monastery. The extent to which the trade in books and the circulation of binding techniques between the monastery and the west was a reflection of the relations of the monastery with its dependencies is also explored.
Rubbings of the approximately 5500 tool impressions on the 1195 decorated bindings have provided the core research material. They have been identified, classified and organized into a descriptive electronic database. Imaging techniques have been developed to compare the scanned impressions, which permitted the identification of impressions of the same finishing tools. Based on the identity of their decorative tools and on the process of comparison of their structural features, a number of the bindings have been ascribed to a total of 70 specific workshops, whose dates and origins are explored. 16 of these workshops - nine from the monastery of St Catherine and seven from elsewhere, which produced bindings imported to the monastery, are discussed analytically. In addition to that, 40 original bookbinding finishing tools were discovered at the monastery during this research, which have provided invaluable material for our understanding of the tooling methods and particularities of decorated book covers at the monastery.
The largest corpus of finishing tools used on Greek bindings to date has been compiled to provide a reference tool which will aid future research on Greek bookbinding.

Toward the standardization of use-wear studies: constructing an analogue to prehistoric hide work by Wiederhold (2004)

Wiederhold, James Edward; Toward the standardization of use-wear studies: constructing an analogue to prehistoric hide work. Master's thesis in Anthropology, Texas A&M University (2004).
URL (OAKTrust)

Abstract:

This thesis is a use-wear study that deals with microwear on stone endscrapers used on one worked material: animal skins. The first part of the study defines and describes the process of rendering freshly skinned pelts into functional leather or rawhide products, addressing confusing terminology found in the literature as well. Problems with past use-wear experiments dealing with animal skins are also confronted and explained. The second part of the study examines endscrapers used to flesh and dehair bison hides and compares the use-wear traces left on the tool edge by each activity. This suite of characteristics is then compared to those found on an assemblage of Clovis-age scrapers from the Gault site in central Texas.

The new website of the Museum of Leather Craft, Northampton (UK)

The Museum of Leather Craft (IMOLC), Northampton (UK)
http://www.imolc.com/

Trunk covered with Russia leather, 1689-1702, Victoria & Albert Museum

“MRI and Unilateral NMR study of reindeer skin tanning processes” by Zhu et al (2015)

Zhu, Lizheng; Del Federico, Eleonora; Ilott, Andrew J.; Klokkernes, Torunn; Kehlet, Cindie; Jerschow, Alexej, “MRI and Unilateral NMR study of reindeer skin tanning processes”, Analytical Chemistry 87(7) (2015) 3820–3825.

DOI:10.1021/ac504474e (ACS Publications, restricted access)

Abstract:

The study of arctic or subarctic indigenous skin clothing material, known for its design and ability to keep the body warm, provides information about the tanning materials and techniques. The study also provides clues about the culture that created it, since tanning processes are often specific to certain indigenous groups. Untreated skin samples and samples treated with willow (Salix sp) bark extract and cod liver oil are compared in this study using both MRI and unilateral NMR techniques. The two types of samples show different proton spatial distributions and different relaxation times, which may also provide information about the tanning technique and aging behavior.

“Use of aluminium alkoxide and oxazolidine II to treat acid-deteriorated historic leather” by Lama et al (2015)

Lama, Anne; Antunes, A. Paula M.; Covington, Anthony D.; Guthrie-Strachan, Jeffry; Fletcher, Yvette;“Use of aluminium alkoxide and oxazolidine II to treat acid-deteriorated historic leather”, Journal of the Institute of Conservation 38(2) (2015) 172–187.

DOI:10.1080/19455224.2015.1071713 (Taylor& Francis Online, restricted access)

Abstract:

This study was undertaken to develop a product that will potentially delay the progress of deterioration of acid-deteriorated historic leather. Acid-deteriorated leather samples were treated with a new formulation consisting of aluminium di(isopropoxide) acetoacetate ester chelate (aluminium alkoxide) and 5-ethyl-1-aza-3,7-dioxabicyclo[3.3.0]octane (oxazolidine II). The leather samples were also treated with oxazolidine II and aluminium alkoxide separately to compare the effectiveness of these reagents against the new formulation. Untreated leather samples were used as a negative control. Acid-deteriorated leather samples treated with Cellugel®, aluminium alkoxide and the new formulation along with corresponding untreated leather samples were also subjected to accelerated ageing in order to investigate the longevity of the treated leather. The impact of the treatments and accelerated ageing was determined by measuring the hydrothermal stability of the leather and pH of the aqueous extract. The formulation showed a potential to provide the acid-deteriorated historic leather with long-term protection against an artificially-created acidic environment.

Resumé:

Cette étude a été menée afin de développer un produit pouvant potentiellement retarder la progression de la détérioration du cuir ancien devenu acide. Des échantillons de cuirs acides ont été traités avec une nouvelle formule composée de chélate d'aluminium d'acétoacétate de di-isopropoxyde (alcoolate d'aluminium) et de 5-éthyl-1-aza-3,7-dioxabicyclo [3.3.0] octane (oxazolidine II). Les échantillons de cuir ont également été traités avec, séparément, de l'oxazolidine II et de l'alcoolate d'aluminium pour comparer l'efficacité de ces réactifs par rapport à la nouvelle formule. Des échantillons de cuirs non traités ont été utilisés comme témoin négatif. Des échantillons de cuirs dégradés par l'acidité traités avec du Cellugel®, de l'alcoolate d'aluminium et la nouvelle formule ainsi que des échantillons correspondant aux mêmes cuirs non traités ont été également soumis au vieillissement accéléré afin d'étudier la longévité du cuir traité. L'impact des traitements et le vieillissement accéléré ont été évalués par une mesure de la résistance du cuir à la chaleur et du pH de l'extrait aqueux. La formule a montré une capacité à fournir au cuir ancien acide une protection de long terme face à un environnement acide artificiel.

“Thermal characterization of new, artificially aged and historical leather and parchment” by Sebestyén et al (2015)

Sebestyén, Zoltán; Czégény, Zsuzsanna; Badea, Elena; Carsote, Cristina; Şendrea, Claudiu; Barta-Rajnai, Eszter; Bozi, János; Miu, Lucretia; Jakab, Emma; “Thermal characterization of new, artificially aged and historical leather and parchment”, Journal of Analytical and Applied Pyrolysis 115 (2015) pp.419–427.
DOI:10.1016/j.jaap.2015.08.022 (ScienceDirect, restricted access)

Abstract:

The aging mechanism of leather and parchment was studied by thermoanalytical methods to understand the effect of the environment on the historical manuscripts and the heritage of libraries and archives. Alkaline and acidic treatments followed by thermal dehydration were applied to achieve chemical changes in the structure of new leather and parchment similar to the slow natural aging of historical samples. Chemical and structural changes during both natural and artificial aging processes were characterized by thermoanalytical techniques. The thermal stability and the evolution profile of the decomposition products under slow heating were studied by thermogravimetry/mass spectrometry (TG/MS). The distribution of the decomposition products of these collagen-based materials under fast pyrolysis was characterized by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). It was found that the maximal rate of the thermal decomposition (DTGmax) significantly decreases by aging in case of both leather and parchment samples indicating the degree of deterioration. Py-GC/MS has been found to be a suitable technique to sensitively monitor the degradation of the polyphenolic components of the vegetable tannins under natural or artificial aging. It was established that the tannin content of leather is more significantly affected by natural aging and alkaline treatment than the main structure of the polypeptide chains. Principal component analysis (PCA) has been used to find statistical correlations between the experimental data for leather samples. The results of the PCA confirmed that the alkaline treatment and the natural aging processes similarly modify the tannin content of the vegetable tanned leather.

Writing box with painted and gilded leather, c.1525, Victoria & Albert Museum