Since pre-historic times people have known have to make a material that we know as leather. In Egypt, vegetable tanned leather was used since the pre-historic period, but the use of parchment dates back to the Middle Kingdom(1). We may consider that since 1884, with the work of Augustus Schultz, thec hrome tanning process began(2). There are a large number of important parchment manuscripts and tanned leathers (vegetable and chrome tanned leather) in archaeological sites (museums, storages, old libraries and excavation areas). From the moment of its creation, parchment or leather starts to age. Ageing as such is a process resulting from damage brought about as a consequence of production technology, environmental conditions, handling and repair(3). Degradation by heat is probably one of the major factors in the deterioration of a large portion of parchment and leather in museum collections(4). There is no doubt that the first stage of any conservation process should always be a detailed study of the condition of the leather with an understanding of the deterioration process in order to present some solutions for the conservation treatment. Most leather artifacts and parchment manuscripts in Egypt usually suffer because of unsuitable environmental conditions(5). A widly used parameter for measuring the condition of parchment and leather is the shrinkage temperature, representing the temperature of which leather has to be heated in an aqueous environment in order to lose its characteristic tridimensional fibre network construction. The loss of this structure causes the leather or parchment to shrink(6).
Reed, R., Ancients skins, Parchments and leathers, Seminar Press, London, 1972, p. 48.
Thomson, R. S., Leather manufacture in the post medieval period withspecial references to Northamptonshire, Post Medieval Arch., London,
1981, p.161.
Larsen, R., Micro methods for the analysis of parchment – MAP – preliminary report, in care and conservation of manuscripts 5, Fellows – JENSEN, Gillian and Springborg, the Royal Library, 2000, pp. 28-37.
Williams, R.S., Surface encrustation on caribon skin coat, Canadian Conservation Institute, Ottawa, Canada, 1982, pp.1-14.
Abdel-Maksoud, G. and Marcinkowska, E., Changes in some properties of aged and historical parchment, Restaurator, Vol. 21, Munich, 2000, p.138.
Larsen, R. Experiments and observation in the study of environmental impact on historical vegetable tanned leathers, Thermochimica Acta, 2000,
p.365. |
References
- Abdel-Maksoud, G. and Marcinkowska, E., Changes in some properties of aged and historical parchment, Restaurator, Vol. 21, Munich, 2000, p.138.
- Abdel-Maksoud, G., Preparation of parchment samples for experimental studies in conservation, Journal of Cracow University of Technology, 1999, 1A, p.154.
- Abdel-Maksoud, G., Preparation of vegetable tanned leather samples for experimental studies in restoration and conservation field, Journal of Cracow University of Technology, Poland, 1999, 1A, pp. 168-181.
- Bickley, J.C., Vegetable tannins, In: Leather, its composition and changes with time, Great Britain, 1991, pp.16-23.
- Bienkiewicz, K. J., Physical chemistry of leather making, Robert E, Krieger Publishing Co. Florida, 1983, pp. 220-236.
- Chahine, C. and Rottier, C., Study on the stability of leather treated with polyethylene glucol, ICOM Committee for Conservation, Interim Meeting on the treatment of and research into leather in particular of ethnographic objects, Amsterdam, 5-8 April, 1995, pp. 77-85.
- Haines, B.M., Shrinkage temperature in collagen fibres, In: Leather Conservation news, Vol.3, No.2, 1987, pp.1-5.
- Haines, B.M., Shrinkage temperature in collagen fibres, In: Leather Conservation News, Vol.3, No. 2, 1987, pp. 1-5.
- Haines, B.M., The physical and chemical characteristics of parchment and the materials used in its conservation, the Leather Conservation Centre, University college Campus, Northampton, 1999, pp. 7-12.
- Halleback, P. B., Impregnation of fragile leather objects, In: 6th International Restorer Seminar (restoration of leather and wood training restorers), the National Centre of Museums, Budapest, Hungary, 1987, p. 197.
- Larsen, R. Experiments and observation in the study of environmental impact on historical vegetable tanned leathers, Thermochimica Acta, 2000, p.365.
- Larsen, R., Micro methods for the analysis of parchment – MAP – preliminary report, in care and conservation of manuscripts 5, Fellows – JENSEN, Gillian and Springborg, the Royal Library, 2000, pp. 28-37.
- Larsen, R., Similarities and differences in the amino acid composition of new, historical and aged leather, In: 6th International Restorer Seminar (restoration of leather and wood training restorers), the National Centre of Museums, Budapest, Hungary, 1987, pp. 205-210.
- Larsen, R., Vest, M and Nielsen, K., Determination of hydrothermal stability (shrinkage temperature), STEP Leather Project (European Commission, Decorative general for Science, Research and development), The Royal Danish Academy of Fine Arts, School of Conservation, Denmark, 1994, pp.151-160.
- Larsen, R., Vest, M., Poulsen, D. V. and Kejser, B., Determination of hydrothermal stability by the micro hot table method, Environmental Leather Project (Deterioration and conservation of vegetable tanned leather, Denmark, 1997, pp. 145 -158.
- Larsen, R., Vest, M., Poulsen, D. V. and Kejser, B., Op.cit. pp. 145-158.
- Matteini, M., Montalbanol, L., Rizzi, M., Scarzanella, C. and Schonhaut, G., Experimental testing of different kinds of fixatives used for the consolidation of painted parchment, International Conference on conservation and restoration of archive and library materials, Istituto Centrale per la Patologia del Libro, Roma, April 22nd – 29th, 1996, p.535.
- Reed, R., Ancients skins, Parchments and leathers, Seminar Press, London, 1972, p. 48.
- Southward, J.A., The effects of photodegradation on collagen: an analysis using the shrinkage temperature method, Master of Art Conservation, Queen’s University, Kingston, Ontario, Canada, 1993, p.16-17.
- Thomson, R. S., Leather manufacture in the post medieval period with special references to Northamptonshire, Post Medieval Arch., London, 1981, p.161.
- Thomson, R.S., A history of leather processing from the medieval to the present time, In: Leather its composition and changes with time, Great Britain, 1991, pp.12-15.
- Williams, R.S., Surface encrustation on caribon skin coat, Canadian Conservation Institute, Ottawa, Canada, 1982, pp.1-14.
- Young, G.S., Microscopical hydrothermal stability measurement of skin and semi-tanned leather, In: ICOM Committee for Conservation, Preprints of the 9th Triennial Meeting, Dresden, 1990, pp. 626-631.
- Young, G.S., Op.cit. pp. 626-631.
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