"The Characterization of Vegetable Tannins and Colouring Agents in Ancient Egyptian Leather from the Collection of the Metropolitan Museum of Art" by Elnaggar et al (2017)

Elnaggar, A.; Leona, M.; Nevin, A.; and Heywood, A., “The Characterization of Vegetable Tannins and Colouring Agents in Ancient Egyptian Leather from the Collection of the Metropolitan Museum of Art”, Archaeometry 59 (2017) 133–147.

doi:10.1111/arcm.12239 (Wiley Online Library, free access)

Abstract:

This work characterizes both tanning and colouring materials found in ancient Egyptian leather objects from the Metropolitan Museum of Art. The analytical investigations focused on assessing the development of the technology of ancient tanners using high-performance liquid chromatography (HPLC), surface-enhanced Raman spectroscopy (SERS), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT–IR), X-ray radiography and a scanning electron microscope connected to an energy-dispersive X-ray detector (SEM–EDX). Reference leather samples and archaeological leather objects were investigated to identify the animal skin species and the early use of hydrolyzable vegetable tannins for leather tanning. Different methods were used to colour th leather, including madder dying and staining with hematite, or painting with Egyptian blue and Egyptian green.

“Feasibility of ultrafast picosecond laser cleaning of soiling on historical leather buckles” by Elnaggar et al (2016)

Elnaggar, Abdelrazek; Fitzsimons, Paul; Lama, Anne; Fletcher, Yvette; Antunes, Paula; Watkins, K. G., “Feasibility of ultrafast picosecond laser cleaning of soiling on historical leather buckles”, Heritage Science 4 (2016) 30.

DOI:10.1186/s40494-016-0104-3 (SpringerOpen, open access)

Abstract:

The aim of the research is to present a system recently developed and used for automated cleaning of artworks and to examine the suitability of using this ultrafast and precise computed-scanning picosecond laser (1064 nm) with a repetition rate of 10 kHz and a temporal pulse length of 10 ps for the removal of soiling from leather buckles without damaging the leather substrate. Preliminary tests will be performed with the model artificially aged vegetable tanned samples to determine the leather damage threshold fluence and the soiling ablation threshold fluence before using a laser for the removal of the soiling from a historical leather buckle. As laser cleaning requires a physical parameterization for optimization of cleaning accompanied with an assessment of the morphological and chemical changes of leather, an investigations were performed to determine the leather damage and ablation threshold fluences of artificially aged and historical vegetable tanned leather using a number of analytical techniques including differential scanning calorimetry, optical microscopy, scanning electronic microscope with energy dispersive X-ray analysis, colorimetry and Fourier transform infrared spectroscopy have been used. Following optimization trials of the picosecond laser cleaning parameters on model leather samples, satisfactory removal of the soiling over the historical leather surface is achieved.

Why Leather? The Material and Cultural Dimensions of Leather by AA.VV. (2014)

Veldmeijer, A. J.; Harris, S. (eds.), Why Leather? The Material and Cultural Dimensions of Leather, Proceedings of the Archaeological Leather Group conference held in 2011, Leiden, Sidestone Press (2014).

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"...Under the microscope with leather" by Christina Duffy, Collection Care blog, The British Library (2013)

Fish skin grain layer: "lixa", sharkskin

Definition of sharkskin in Matt T. Roberts and Don Etherington, Bookbinding and the conservation of books: A dictionary of descriptive terminology, 1982

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Fish skin grain layer: shagreen (Hypolophus sephen)

Definition of shagreen in Matt T. Roberts and Don Etherington, Bookbinding and the conservation of books: A dictionary of descriptive terminology, 1982
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