"A Great Lakes pouch: black-dyed skin with porcupine quillwork" by Cruickshank et al (2009)

Cruickshank, P.; Daniels, V.; King, J.; “A Great Lakes pouch: black-dyed skin with porcupine quillwork”, British Museum Technical Research Bulletin 3 (2009) 63-72

PDF

Summary: 

A late eighteenth-century North American pouch (1937,0617.1) represents an important type of a black-dyed skin bag decorated with porcupine quillwork. The pouch was made by women of the Ojibwa or Ottawa people and was probably used in medicine ceremonies. It came to the British Museum in the mid-twentieth century and when first examined in detail in the 1970s had already deteriorated. The skin has degraded due to the presence of a black dye, although an early watercolour painting of the bag discovered in the 1990s illustrates how the bag once looked. Black dyes containing both iron and tannin are well known to increase the rate of deterioration of many organic substances and the pouch was found to contain 1.63% iron. Experiments with a series of brain-tanned skin samples stained with various iron-tannin solutions and artificially aged showed that the presence of iron accelerated the deterioration of the skin.

A conservation treatment carried out in the 1970s, which included consolidation with soluble nylon and backing with nylon net adhered with an early thermoplastic adhesive, was no longer succeeding in keeping the bag intact, and further conservation was carried out to protect the 75% of the bag that survives. As the pouch is of a rare type it was decided to infill the missing areas to make it more suitable for display. The use of adhesives was kept to a minimum and solvent-reactivated adhesives were chosen in preference to those reactivated by heat. No further chemical stabilization was attempted in this treatment.

"On oxidative degradation of parchment and its non-destructive characterisation and dating" by Možir et al (2011)

Možir, A.; Strlič, M.; Trafela, T.; Kralj Cigić, I.; Kolar, J.; Deselnicu, V.; Bruin, G.; “On oxidative degradation of parchment and its non-destructive characterisation and dating”, Applied Physics A: Materials Science & Processing 104 (1) (2011) 211-217

DOI: 10.1007/s00339-010-6108-z (restricted access)

Abstract:

Historic parchment is an extremely complex material, not only due to the various methods of production used and various past environmental histories of objects, but also due to its inhomogeneous structure. Many traditional methods of characterisation are empirical, but useful since they have gained recognition by the end-users. In this paper, we investigated the shrinkage temperature of collagen and the influence of lipids contained in parchment on the measurements. While the content of lipids does not seem to significantly affect shrinkage temperature measurements themselves, it strongly affects the decrease of shrinkage temperature of collagen during degradation, and thus its thermomechanical properties. This confirms the high importance of lipid peroxidation during degradation of parchment. While shrinkage temperature determination is a micro-destructive method, we also demonstrated that it is possible to determine this property using near infrared (NIR) spectroscopy based on partial least squares calibration. The root-mean square error of validation (RMSEV), obtained on a set of variously delipidised and degraded samples, was 7°C, so the method could be used for condition assessment or classification of historic objects. Using a set of 185 historic objects dating from 1200–1800, we also developed a method for non-destructive dating of parchment based on NIR spectroscopy using partial least squares regression (RMSEV=72 years), and successfully determined the correct age of a historic charter from the collection of Nationaal Archief, The Netherlands. 

Leather working by Hasluck (1904)

Hasluck, P. N.; Leather working, D. McKay, Philadelphia (1904)

InternetArchive 

Preface: 

This Handbook contains, in a form convenient for everyday use, a comprehensive digest of the information on Leather Working, scattered over more than twenty thousand columns of Work — one of the weekly journals it is my fortune to edit — and supplies concise information on the details of the subjects on which it treats.

In preparing for publication in book form the mass of relevant matter contained in the volumes of Work, much had to be arranged anew, altered, and largely re-written. From these causes the contributions of many are so blended that the writings of individuals cannot be distinguished for acknowledgement.

Readers who may desire additional information respecting special details of the matters dealt with in this Handbook, or instructions on kindred subjects, should address a question to Work, so that it may be answered in the columns of that journal.

Fauteuil transatlantique by Eileen Gray, 1925-1930, Victoria & Albert Museum

"The re-treatment of an Inuit beaded skin parka" by Dumka (2006)

Dumka, Heather; "The re-treatment of an Inuit beaded skin parka", Journal of the Canadian Association for Conservation (J. CAC) 31 (2006) 23-32

PDF

Abstract:

This paper describes the treatment of a badly damaged Inuit parka made of caribou skin and decorated with heavy, beaded fabric panels. The parka was originally repaired in 1967 when most of the panels were restored by re-beading and lining with new fabric, and the skin was repaired with sewn leather patches. This earlier restoration distorted the shape of the parka and did not stabilize the skin, resulting in further tears. The re-treatment of the parka involved removing all of the previous skin repairs as well as the beaded panels. Tears and losses in the skin were patched using BEVA 371 sprayed onto a spun-bonded nylon fabric (Cerex). The parka was then lined with Cerex to provide additional support for the beaded panels, which were stitched back into place. One of the panels, which had not been previously restored, was stabilized and lined onto new fabric prior to reattachment.

Resumé:

Cet article décrit le traitement d'un parka inuit très endommagé, fait en peau de caribou et orné de panneaux en tissu sur lesquels se trouvent de lourdes broderies en perles de verre. Un traitement datant de 1967 avait occasionné la pose de nouvelles perles sur presque tous les panneaux de broderies ainsi que de tissus de soutien sous les panneaux, et la réparation de la peau à l'aide de pièces de cuir cousus aux endroits endommagés. Ce traitement provoqua des distortions à la conformation du parka et ne réussit pas à stabiliser la peau; au contraire de nouvelles déchirures apparurent. Le re-traitement de ce parka consista à retirer les anciens rapiéçages ainsi que les panneaux perlés. Un non-tissé en nylon (Cerex) sur lequel fut pulvérisé du BEVA 371 servit à réparer les peaux déchirées et à combler les lacunes. Ensuite, le parka dans son ensemble fut aussi renforcé au moyen d'un doublage, à l'aide de Cerex et de BEVA 371, afin de mieux soutenir le poids des panneaux perlés, qui furent ensuite recousus en place. Un des panneaux, qui n'avait pas fait l'objet d'une restauration antérieure, fut stabilisé et doublé sur un tissu neuf avant d'être recousu en place.

Cabinet, Venice (?), 1580-1600, Victoria & Albert Museum

"Creación de un protocolo de la encuadernación que permita controlar el proceso de su restauración" por Díaz-Miranda y Macías (2007)

Díaz-Miranda y Macías, M. D.; "Creación de un protocolo de la encuadernación que permita controlar el proceso de su restauración", La conservación infalible: de la teoría a la realidad, Actas del III Congreso do Grupo Español del IIC, Madrid (2007) 205-222
PDF

Brownie, Kodak camera, 1950-1959, Victoria & Albert Museum

"La encuadernación de los libros de coro (...)" por Bueno Vargas (2005)

Bueno Vargas, J.; “La encuadernación de los libros de coro: las cubiertas de los cantorales de la Abadía del Sacromonte de Granada”, PH Boletín del Instituto Andaluz del Patrimonio Histórico 53 (2005) 58-69

PDF

Resumen:

Los libros de coro constituyen una tipología muy específica dentro de la historia del libro. Su uso en diferentes instituciones religiosas condicionó tanto su formato, estructura y encuadernación, como los materiales con que se realizaron y los acabados que éstos recibieron. Hoy en día destacan por el mal estado de conservación que en general presentan al haber quedado almacenados en vitrinas o archivos o en sótanos, buhardillas o armarios. En este artículo nos centramos en las particularidades de una colección de cantorales cuyo núcleo principal se confeccionó durante los siglos XVII y XVIII, analizando tanto los materiales como los acabados y sistemas de protección de la encuadernación. Son éstos elementos fundamentales en esta tipología y su estudio suele quedar relegado cuando se abarca el análisis de alguna de estas colecciones. Sirva este trabajo para dedicarles la atención que merecen, no sólo como obras de arte que son, sino por su valor antropológico como objetos fundamentales para entender a la sociedad que los creó y los consideró elementos indispensables en los ritos religiosos.

"Leather material found on a 6th B.C. Chinese bronze sword: a case study" by Luo et al (2011)

Luo, W.; Si, Y.; Wang, H.; Qin, Y.; Huang, F.; Wang, C.; "Leather material found on a 6th B.C. Chinese bronze sword: a case study", Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 79(5) (2011) 1630-1633

doi:10.1016/j.saa.2011.05.023 (restricted access)

Abstract:

During July to November, 2006, an important archaeological excavation was conducted in Yun country, Hubei province, southern China. Chinese archaeologists found some remnant of leather materials, covered with red pigments, on a 6th century B.C. Chinese bronze sword. To understand the technology/ies that may have been utilized for manufacturing the leathers, a combined of Raman spectroscopy, FT-IR and XRF was thus applied to the remnant of leather materials. Raman analyses showed that red pigment on the leather was cinnabar (HgS). FT-IR and XRF analyses indicated that the content of some elements, such as Ca (existing as CaCO₃) and Fe (existing as Fe₂O₃), were much higher than those in the surrounding grave soil. The results inferred an application of lime depilation and retting, and the Fe–Al compound salt as tanning agent. And it was furthermore implicated that the Fe–Al salt tanning technique had been developed in the middle and late Spring and Autumn Period of China.

Purse, 1630, The MET Museum of Art

Pilot aviation helmet, 1918-19, National Postal Museum, Smithsonian Institution

SI Collections Search Center: Pilot Edward Gardner’s aviation helmet

"Tannins characterisation in new and historic vegetable tanned leathers fibres by spot tests" by Falcão and Araújo (2011)

Falcão, L.; Araújo, M. E. M.; "Tannins characterisation in new and historic vegetable tanned leathers fibres by spot tests", Journal of Cultural Heritage 12(2) (2011) 149-156

doi:10.1016/j.culher.2010.10.005 (restricted access)

Abstract: 

This paper describes the adaptation and evaluation of three chemical tests for tannins characterisation in vegetable tanned leathers. Tests were performed on fibres of new leathers tanned with different known vegetable tannins and historic leathers. Rhodanine test, nitrous acid test and acid butanol test, developed to identify, respectively, gallotannins, ellagitannins and condensed tannins, are described. Ferric test and vanillin test, the two traditional tests used for vegetable tanned leathers characterisation, were also performed and their usefulness discussed. Gallic acid, ellagic acid and catechin, structural constituents of the different classes of tannins were also tested. Results of the developed methodology allowed the identification of tannins’ chemical class in new and historic leather samples studied. Data obtained permitted to verify the information on tanning materials used in new leathers. Vegetable tanning technology was confirmed in historic samples and tannins were characterised. This study shows that these tests are useful and can be a valuable source of information to evaluate new vegetable tanned leathers quality for conservation and restoration purposes as well as historic leathers tanning technology.

Khamsa (Quintet) of Nizami, 1510, The MET Museum of Art

"Khamsa (Quintet) of Nizam [Shiraz, Iran] (13.228.6)". In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/works-of-art/13.228.6 (March 2007)

The leather specimen book by La Croix (1917)

La Croix, F. W.; The leather specimen book, Milwaukee (1917)
URL (Internet Archive)


Preface:

The many requests for information about leather that are constantly received by the advertising department of the Pfister & Vogel Leather Co. from merchants of leather goods and teachers and students in schools and colleges prompted the publication a few years ago of "How Leather Is Tanned." This pamphlet in a few mimeographed pages undertook to tell in a simple, concise fashion the essential facts in the manufacture of leather and to fill in some measure the almost total lack of descriptive, non-technical works on tanning.  Though a great many copies of "How Leather Is Tanned" have been supplied to interested persons, it has been evident that it went only part way with regard to instruction in leather and its manufacture. 

The common experience seems to have been that it is difficult to get a clear grasp of the subject without the opportunity of inspecting typical samples of leather in connection with the reading. It is as an aid in this respect that "The Leather Specimen Book" has been prepared. Used in connection with "How Leather Is Tanned" it aims to give a knowledge of leathers and the process of tanning sufficiently complete for all purposes not connected with practical tanning. 

On account of the almost unlimited variety in methods of finishing leather it has been possible to show only the most common and representative types of finishes. In using this book to identify leather it should be kept in mind that a tanned skin may be embossed and finished so as to have its true nature totally disguised.

Anchorage Loan Conservation Project: conservation case studies - NMNH kayak

Anchorage Loan Conservation Project: Conservation Case Studies  

NMNH kayak: Revising Cultural Attributions and Monitoring Change

URL

"The use of thermal analysis methods for authentication and conservation state determination of historical and/or cultural objects manufactured from leather" by Budrugeac et al (2011)

Budrugeac, P.; Cucos, A.;  Miu, L.; “The use of thermal analysis methods for authentication and conservation state determination of historical and/or cultural objects manufactured from leather”, Journal of Thermal Analysis and Calorimetry 104(2) (2011) 439-450 

DOI: 10.1007/s10973-010-1183-0  (restricted access)

Abstract:

Leather products have been useful materials since the dawn of human history. Many leathers objects are valuable treasures due to the history they represent, and their preservation challenges museum custodians and private collectors alike. In this article, the applications of thermal analysis methods (Micro Hot Table (MHT), thermogravimetry/derivative thermogravimetry (TG/DTG), dynamic scanning calorimetry (DSC), differential thermal analysis (DTA), and dynamic mechanical analysis (DMA)) for the characterization of the recently manufactured and old leathers are presented. These methods can be used for the assessment of deterioration degree of leathers, and, therefore, the data obtained by these techniques could be useful for achievement of the suitable preservation procedures as well as the effects of conservation treatments. In addition, it was pointed out that these methods are suitable for qualitative distinction between the recently manufactured leathers and heritage items.

"Characterisation and evaluation of the environmental impact on historical parchments by DSC" by Badea et al (2011)

Badea, E.; Della Gatta, G.; Budrugeac, P.; “Characterisation and evaluation of the environmental impact on historical parchments by differential scanning calorimetry”, Journal of Thermal Analysis and Calorimetry 104(2) (2011) 495-506

DOI: 10.1007/s10973-011-1495-8 (restricted access)

Abstract:

Our recent developments concerning the assessment of parchments deterioration using DSC are reported. Measurements performed on samples in excess water conditions, in static air and gas flow provided qualitative and quantitative information on parchment ageing and deterioration at microscopic and mesoscopic level, when assembly of fibres/fibrils is weakened, partially and eventually completely lost, and at molecular level, when triple helix uncoiling occurs. A damage ranking scale based on a large collection of DSC parameters obtained by investigating artificially aged samples was set up. Deconvolution of the DSC thermal denaturation peaks in excess water enabled evaluating and discriminating stability of parchments with similar damage levels. Further experimental evidences such as softening of the crystalline fraction of collagen, thermal-oxidation and collagen gelatinisation were detected by DSC measurements in gas flow and static air, and related to specific deterioration patterns. DSC measurement of wet samples provided an objective and reliable method for evaluating parchment shrinkage temperature overcoming the limitations of conventional methods.

 

"An easy-to-build museum saddle mount" by Shevchuk (2009)

Shevchuk, Paul; "An easy-to-build museum saddle mount", Conserve O Grams 9/2 (2009)
PDF

From the introduction:

This Conserve O Gram provides guidance on how to build a mount to support and store a large saddle with component parts (straps, stirrups) in the way it was intended to be used. This mount is strong, light-weight, and easy to move or transport, and uses cabinet space efficiently.

"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.