Publication details

Comparative study of archaeological and historical leather testing



Year of publication 2016
Type Conference abstract
MU Faculty or unit

Faculty of Science

Description The term “leather” covers a wide range of related materials as rawhide, parchment, suede etc. which share a lot of features but other characteristics are rather different. The state of leather depends on the raw material, manufacturing processes and on the type and degree of deterioration as well. All of the properties determine which methods can and should not be used during conservation. A variety of methods were described for quality testing, rawhide determination or degree of decay. Rawhide can be determined with a little experience and minimal equipment (visual examination, magnifying glass or microscope). DNA analysis can be applied as well, but it is very expensive and hardly available. Also tanning matter can be determined in several ways. Ashing test and spot test are easy, available, require only a small amount of sample (mg) but they are only indicative (chrome/vegetable tanned). FTIR analysis is more specific but it is time-consuming, necessitates larger amount of sample (g) and instrument has to be operated by a skilled operator. Decay degree determination is the most important examination for subsequent conservation. It can be determined in a several ways. The pH value determination is the most common and easiest method giving us the information about free acids present in leather. Other essential information is the shrinkage temperature (Ts) providing us knowledge about irreversible chemical changes in collagen structure. Mechanical properties such as tensile strength and elongation at break inform us about physical and chemical changes in leather. All mentioned methods were thoroughly tested and described in literature and some of them were even standardized for new and historical leather testing, but no method has been recommended as suitable for archaeological leather testing yet. The aim of this work is to verify above mentioned methods for archaeological material, compare the results with historical material and suggest the most promising methods for archaeological leather testing.