2nd Edition
Conservation of Leather, Skin and Related Materials
Acknowledgements
List of Contributors
List of Figures
List of Tables
Introduction - Arianne Panton and Rosie Bolton
Part 1: Context
1. The Evolution and Development of Leather and Leather Producers - Mike Redwood
1.1. Introduction
1.2. Earliest times
1.2.1. Early treatments
1.2.2. Early physical samples
1.3. The horse
1.3.1. Wheels, reins and saddles
1.3.2. Horses and military leathers
1.3.3. Fighting chariots
1.4. Roman military leather demand
1.5. Agriculture and trade
1.5.1. Horse collars and shoes
1.6. The advance of modern industry
1.7. Industrial leathers
1.7.1. Machinery advances and new buildings
1.8. Leather chemistry
1.9. Luxury
1.9.1. Moroccan leather
1.9.2. Córdoban leather
1.9.3. Luxury and the Renaissance
1.10. Guilds and livery companies
1.11. Modern times
1.12. Conclusions
References
2. Tools and techniques - Caroline Darke and Fflur Owen
2.1. Leather working tools
2.1.1. The awl
2.1.2. The knife
2.1.3. The strop
2.1.4. The bone folder
2.1.5. The revolving hole punch
2.1.6. The hammer
2.1.7. The race
2.1.8. The clam or stitch pony
2.1.9. The edge shaver or beveler
2.1.10. The crease iron
2.1.11. The stitch marker
2.1.12. The pricking iron
2.1.13. The needle
2.1.14. Thread
2.2. Adhesives
2.3. Linings and reinforcements
2.4. Techniques
2.4.1. Skiving
2.4.2. Preparation
2.4.3. Sewing
2.4.4. Decorative stitching
2.4.5. Machine and decorative stitching
2.5. Seams and construction
References
Part 2: The Raw Material
3. Collagen: The Leather Making Protein - Original text by Betty. M. Haines. Reviewed by Tim Cleland and Alexandra Popowich
3.1. The collagen Molecule
3.2. Bonding within the molecule
3.3. Bonding between molecules
3.3.1. Salt bridges
3.3.2. Covalent intermolecular bonding
3.4. Fibril structure
3.5. Shrinkage Temperature
References
4. The Fibre Structure of Leather - Original text by Betty. M. Haines. Revised by Mark Gummer
4.1. The structure of mammalian skin
4.2.1. Mature cattle skins
4.2.2. Calfskin
4.2.3. Water Buffalo
4.2.4 Goatskin
4.2.5. Sheepskins
4.2.6. Deerskins
4.2.7. Pigskins
4.3. Grain surface patterns
4.4. Sueded surfaces
4.5. Variation in structure with location in the skin
4.6. Directional run of the fibres
4.7. The influence of fibre structure on leather properties, structure and tear strength
4.8. Structure and leather handle
4.9. Fibre weave and movement
References
5. Leather and skin damage and defects - Mark Gummer
5.1 Introduction
5.2. Natural damage
5.2.1. Natural Characteristics
5.2.2 Parasite damage
5.2.3. Disease
5.2.4. Mechanical
5.3. Postmortem damage
5.4. Processing damage
5.5. Summary
References
6. Analytical techniques used in the study of leather and skin materials - Alexandra Popowich and Arianne Panton. Contributions by Will Wise, Marianne Odlyha, Elena Badea, Christine Carsote, Matthew Collins and Timothy Stinton
6.1. Introduction
6.1.1. Challenges of analysing leather and skin materials
6.1.2. Practical considerations
6.2. Thermal/mechanical analysis (by Marianne Odlyha, Elena Badea and Cristina Carsote)
6.2.1. Micro hot-table measurement (MHT)
6.2.2. Micro-differential scanning calorimetry (micro-DSC)
6.2.3. Thermogravimetric analysis (TGA)
6.2.4. Dynamic mechanical analysis (DMA)
6.3. Structural morphology
6.3.1. Surface morphology imaging
6.3.2. Chemical imaging
6.4. Chemical composition
6.4.1. Spot tests
6.4.2. Elemental and isotopic analysis
6.4.2.1. Inductively coupled plasma mass spectroscopy (ICP-MS)
6.4.2.2. X-ray fluorescence spectroscopy (XRF)
6.4.2.3. Scanning electron microscopy with energy dispersive electron microscopy (SEM-EDX)
6.4.3. Functional groups
6.4.3.1. Fourier transform infrared (FTIR)
6.4.3.2. Raman spectroscopy
6.4.4. Small molecules (e.g. dyes, tannins, oils/fats)
6.4.4.1. Spot tests
6.4.4.2. High performance liquid chromatography (HPLC)
6.4.4.3. Liquid chromatography-mass spectroscopy (LC-MS) and tandem mass spectroscopy (LC-MS/MS)
6.4.4.4. Matrix-assisted laser desorption/ionisation (MALDI) mass spectroscopy
6.4.4.5. Gas chromatography-mass spectroscopy (GC-MS)
6.5. Biological origin
6.5.1. Antibody-based detection
6.5.1.1. Immunological techniques
6.5.2. Proteomics
6.5.2.1. Zooarchaeology by mass spectroscopy (ZooMS) (by Matthew Collins)
6.5.2.2. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)
6.5.3. Genomics (by Timothy Stinson)
6.5.3.1. Polymerase chain reaction (PCR)
6.5.3.2. Next-generation sequencing (NGS)
References
Part 3: Leather and Skin for Conservators
7. Overview of skin-based materials and approaches to conservation - Arianne Panton and Rosie Bolton
7.1. Introductions
7.2. Terminology
7.3. Common processing stages
7.3.1. Subtractive
7.3.2. Additive
7.3.3. Mechanical
7.4. An introduction to identifying skin-based materials
7.4.1. Challenges of identification
7.5. Mechanisms of deterioration
7.5.1. Chemical deterioration
7.5.2. Physical
7.5.3. Biological deterioration
7.6. Common conservation approaches
7.6.1. Documentation
7.6.2. Cleaning
7.6.3. Consolidants
7.6.4. Adhesives
7.6.5. Repair and support materials
7.6.6. Infilling and casting materials
7.6.7. Humidification and reshaping
References
Part 3.1. Tanned and Processed skin Materials
8. The Conservation of Parchment - Chris Woods
8.1 Introduction
8.2 Parchment Production and Use
8.3 Chemical, physical and deterioration characteristics
8.4 Display and storage
8.5 Conservation treatments
8.5.1 Mould and fumigation
8.5.2 Cleaning methods
8.5.3 Humidification and softening
8.5.4 Consolidation of weak parchment
8.5.5 Consolidation of inks and pigments
8.5.6 Repairs and supports
8.6 Conclusion
8.7 Case Study: Conservation of Lincoln Cathedral’s Magna Carta and Forest Charters
References
9. Animal fat, organ, oil, and smoke processed skins - Theresa Emmerich Kamper, Alexsandra Popowich and Fran Ritchie
9.1. Introduction
9.2. Terminology
9.3. Processing methods
9.3.1. Subtractive stage
9.3.2. Additive stage
9.3.3. Mechanical stage
9.4. Chemistry
9.4.1. Subtractive stage
9.4.2. Additive stage
9.5. Physical and behavioural characteristics
9.5.1. Physical
9.6. Identification
9.6.1. Visual
9.6.2. Chemical
9.7. Conservation considerations
9.7.1. Community consultation
9.7.2. Health and safety
9.7.3. Condition issues
9.8. Conservation
9.8.1. Preventive
9.8.2. Interventive
9.9. Case studies
9.9.1. Moccasins
9.9.2. Footstool
9.9.3. Painted hide
References
10. Gut and Membrane Materials - Ellen Carrlee and Amy Tjiong
10.1. Introduction and geo-historic context
10.1.1. Arctic
10.1.2. Other regions
10.1.3. Archaeology
10.1.4. Musical instruments
10.2. Characteristics and visual identification
10.2.1. Intestine
10.2.2. Stomach
10.2.3. Esophagus
10.3. Methods of analysis
10.3.1. Visual examination
10.3.2. Histology
10.3.3. Instrumental analysis
10.3.4. Biomolecular techniques
10.3.5. Case study: Gt parka identification in Alaska/Siberia
10.3.6. Stylistic properties and species identification by region
10.4. Manufacture
10.4.1. Processing intestine
10.4.2. Other organs
10.4.3. Sewing
10.4.4. Embellishments
10.5. Deterioration of gut and membrane materials
10.5.1. Tearing
10.5.2. Distortion
10.5.3. Soiling
10.5.4. Special concerns for winter gut
10.5.5. Lined gut items
10.5.6. The threat of insect damage
10.6. Historic treatments
10.6.1. Cultural repairs
10.6.2. Lubricants in cultural and museum use
10.6.3. Case study: Elaine Kingeekuk
10.7. Current conservation approaches
10.7.1. Cleaning
10.7.2. Reshaping
10.7.3. Repair of tears and losses
10.8. Storage and exhibition
10.8.1. Storage and the preservation environment
10.8.2. Exhibition
10.8.3. Case study: The visceral exhibit
References
11. Alum-tawed skins - Liza Foley, Élodie Lévêque, Cédric Lelièvre and Laurianne Robinet
11.1. Introduction
11.2. Characteristics of alum tawed skins
11.3. Geo-historic context
11.4. Historic manufacturing
11.4.1. Historic recipes
11.5. Analytica techniques used in the identification and assessment of alum tawed skins
11.6. Deterioration of alum tawed skins
11.6.1. Pink discolouration caused by alum tawing
11.6.2. Acid hydrolysis
11.6.3. Impact of humidity on alum-tawed skins
11.7. Conservation approaches
11.7.1. Cleaning and infills
11.7.2. Adhesives for treatment
11.8. Conclusions
References
12. Vegetable tanned leather - Arianne Panton, Rosie Bolton. Contributions by Tony Covington and René Larsen
12.1. Introduction
12.2. History and manufacture of vegetable tanned leathers
12.2.1. Vegetable tannins
12.2.2. Traditional processing methods
12.2.3. Industrial tanning methods
12.2.4. Post-tanning processing methods
12.3. The chemistry of vegetable tannins
12.3.1. Hydrolysable tannins
12.3.2. Condensed tannins
12.4. Examination and identification of vegetable tanned leather
12.4.1. Organoleptic properties
12.4.2. Spot testing
12.4.3. Analytical techniques
12.4.4. Identifying subcategories and other related materials
12.5. Chemical deterioration of vegetable tanned leather
12.5.1. Acid hydrolysis and oxidation
12.5.2. Assessing chemical degradation using B/A ratio and sulphate content
12.5.3. The influence of sulphur dioxide pollution
12.5.4. The impact of moisture
12.5.5. The isoelectric point (pl) and pH influence on collagen swelling
12.6. Assessing degradation using analytical techniques
12.6.1. Acid hydrolysis
12.6.2. Oxidation
12.6.3. Mechanical deterioration
12.7. Common condition issues in objects made from historic vegetable tanned leather
12.7.1. Red rot
12.7.2. Age hardening
12.7.3. Delamination
12.7.4. Metal interactions
12.7.5. Fatty spews
12.8. Conservation approaches and materials
12.8.1. Cleaning
12.8.2. Consolidation
12.8.3. Adhesives
12.8.4. Repair and support materials
12.8.5. Infilling and casting materials
12.8.6. Dressings and finishes
12.9. Case study: Conservation of a leather bottle from Chiddingstone Castle
12.10. Case study: Treatment of a Kukri machete sheath wrapped in adhesive electrical tape
References
13. Mineral-Tanned Leather - Marina Kastan and Tony Covington
13.1. Introduction
13.2. Chemistry of chrome tanning
13.3. Additional processing of chrome-tanned leather
13.4. Tanning with other metals
13.5. Degradation of chrome-tanned leather
13.6. Conservation approaches to chrome -anned leather
13.7. Case study
References
Part 3.2 Further Manufacturing
14. Taxidermy - George A. Dante, Jr., Linda Nieuwenhuizen and Fran Ritchie
14.1. A brief history of taxidermy
14.2. Construction techniques and common condition issues
14.2.1. Terminology
14.2.2. Mammal taxidermy
14.2.3. Avian taxidermy
14.2.3. Ichthyological taxidermy
14.2.4. Herpetological taxidermy
14.2.5. Study skins
14.3. Conservation health and safety
14.3.1. Types of residual pesticides
14.3.2. Working with taxidermy
14.4. Conservation approaches
14.4.1. Preventive conservation
14.4.2. Interventive conservation
14.5. Case studies
14.5.1. African elephant with water damaged trunk
14.5.2. Skunk with hair loss
14.5.3. Owl detached from base
14.5.4. Brook trout and Rudd fish with damaged and missing fins
14.5.5. Great Basin rattlesnake with skin loss
References
15 Archaeological Leather and Skin - Angela Middleton and Lucy Skinner
15.1. Introduction
15.2. Survival of leather in archaeological contexts
15.2.1. Waterlogging
15.2.2. Desiccation
15.2.3. Mineral preservation
15.3. archaeological fieldwork
15.3.1. In situ recording and documentation – conserving information
15.3.2. Planning
15.3.3. Field conservation
15.3.4. Onsite treatments
15.3.5. Lifting
15.3.6. Transport
15.4. Post excavation measures
15.4.1. Waterlogged leather
15.4.2. Desiccated skin and leather
15.4.3. Mineral preserved skin and leather
15.5. Conservation
15.5.1. Wet / Waterlogged leather
15.5.2. Desiccated and frozen leather
15.5.3. Mineral preserved leather
15.5.4. Case study: Waterlogged leather
15.6. Investigation and analysis of archaeological leather
15.6.1. Investigating colour
15.6.2. Visual conditions assessment
15.6.3. Differential scanning calorimetry (DSC) and shrinkage temperature (Ts)
15.6.4. Imaging techniques
15.6.5. Scientific dating
15.6.6. Investigating hide and skin selection
15.6.7. Investigating hide and skin preparation methods
15.6.8. Investigating colour
15.6.9. Investigating the microbiome
15.6.10. Interpreting imperfections on hide and skin
15.7. Storage and display
15.8. Conclusion
References
16. Bookbinding Leather - The leather discussion group: Katherine Wagner, Kristi Wright, William Minter, Holly Herro. Additional authors: René Larsen, Jeff Peachy, Don Ethington, Herre de Vries
16.1 Introduction
16.2 History of Bookbinding Leather Research
16.3 Characteristics of Bookbinding Leather
16.4 Regional Variations in Historic Leather Use for Bookbinding
16.5 Physical Testing of Bookbinding Leathers
16.6 Imaging Leather Bindings
16.7 Consolidants and Coatings
16.8 Treatment Techniques
16.8.1 Japanese Paper Hinge
16.8.2 Board Reattachment
16.8.3 Rebacking
16.8.4 Rebinding/Recovering
16.8.5 Spue
16.8.6 Dyes
16.8.7 Paring leather
16.8.8 Adhesives
16.9 Tools
16.10 Conclusions
16.11 Case Study: Rebacking the Martyr’s Mirror
16.12. Shagreen on Bookbindings – the importance of identification in treatment decision making – Herre de Vries
16.12.1. Types of land mammal shagreen and identification
16.12.2. Case study: Shagreen binding
References
17. Gilt Leather - Céline Bonnot-Diconne and Laurianne Robinet
17.1. Introduction
17.2. Manufacturing
17.3. Analysis
17.4. Degradation of gilt leather
17.5. Conservation
17.5.1. The condition report
17.5.2. The main stages in conservation
17.6. Case studies
17.6.1. A gilt leather wall-hanging
17.6.2. A gilt leather alter frontal
17.6.3. A gilt leather folding screen
17.6.4. A chair upholstered with gilt leather
References
18 Moulded and Rigid Leather and Skin Materials - Rosie Bolton with contributions from Fleur Dingen
18.1. Introduction
18.2. Cuir Bouilli
18.3. An overview of traditional techniques
18.3.1. Vegetable tanned leather-based materials
18.3.2. Rawhide-based materials
18.4. Identifying possible construction methods
18.5. Conservation approaches
References
19. Conservation of East Asian Lacquer on Leather - Shayne Rivers and Lauren Piper
19.1. Introduction: what is lacquer
19.2. Geo-historic context: East Asian lacquer
19.3. Manufacture
19.4. Characteristics, methods of ID and analysis
19.4.1. Examination: what to look for
19.4.2. Checklist for East Asian lacquer on leather condition report – what to look for
19.5. Specific deterioration phenomena
19.5.1. Degradation: light
19.5.2. Degradation: cracking and delamination
19.6. Conservation approaches
19.6.1. Cleaning options
19.6.2. Conservation: photodegraded surfaces
19.6.3. Conservation: cracking & delamination
19.6.4. Conservation: filling & retouching
19.7. Historic conservation approaches
19.8. Health & safety
19.9. Preventive conservation
19.20. Case study: conservation of a Japanese shoulder guard (o sode)
References
20. Surface Finishes in the latter 20th Century - Paul Evans and Brenda Keneghan
20.1. Introduction
20.2. Leather crusts: Impact on finishing operations and final properties
20.3. Finishing materials
20.3.1. Natural finishing materials (film forming)
20.3.2. Synthetic finishing materials (film forming)
20.3.3. Diluents and solvents
20.3.4. Non-film forming materials – natural and synthetic
20.4. Process engineering
20.4.1. Application methods
20.4.2. Physical operations
20.5. Summary of finished leathers
20.6. Degradation of polymers
20.7. Identification of polymers
20.7.1. Dating / chronology
20.7.2. Microchemical tests
20.7.3. Instrumental techniques
20.7.4. Conservation (preservation) of polymers
20.8. Glossary of terms
20.9. Appendix: Some common general finishing guidelines
References
Part 3.3. Associated Materials
21. Aquatic (Fish) Skins - Elisa Palomino, Lotta Rahme, June Pardue, Anatoly Donkan, Sophie Rowe-Kancleris and Courtney VonStein Murray
21.1 Cultural context
21.1.1 Alaska native peoples
21.1.2 Amur river indigenous peoples: The Hezhe
21.1.3. Amur river indigenous peoples: The Nivkh, Nanai and Ulchi
21.1.4 Ainu indigenous peoples
21.1.5 Scandinavian peoples
21.1.6 Icelanders
21.2 Nature and characteristics of fish leather
21.3 Traditional knowledge
21.4 Fish skin processing methods
21.4.1 Traditional tanning
21.4.2 Industrial tanning
21.4.3 Traditional dyeing
21.5 Sewing methods
21.6 Contemporary use of fish skin
21.7 Deterioration and conservation
21.7.1 Common condition issues
21.7.2 Treatment approaches
21.7.3 Case Study: Repair and re-shaping of two Yu’pik fish skin bags
21.7.4 Case Study: Local humidification and repair of two Nivkh coats
References
22. Ray and Shark Skin - Cathy Silverman
22.1. Distinguishing between ray and shark skin and their imitations
22.2. History of use and object types
22.3. Species
22.3.1. Ray species
22.3.2. Shark species
22.4. Methods of manufacture
22.4.1. Raw hide preparation
22.4.2. Cleaning skins
22.4.3. Non-tanning preparations
22.4.4. Tanning
22.4.5. Grinding, polishing and denticle removal
22.4.6. Dyes and colourants
22.4.7. Application
22.4.8. Coatings
22.5. Conservation
22.5.1. Properties of skin and common condition issues
22.5.2. Treatment approaches
References
23. Reptilian Skins - Arianna Bernucci, Efstratia Verveniotou and Patrick Campbell
23.1. Introduction
23.2. Reptile skin structure
23.2.1. The epidermis
23.2.2. The dermis
23.3. Identification of skins in the animal skin trade
23.4. Skin management and tanning
23.5. Conservation
23.5.1. Deterioration and condition assessment
23.5.2. Cleaning
23.5.3. Humidification/Re-shaping
23.5.4. Consolidation, repairs and loss compensation
23.5.5. Preventive conservation
References
24. Furskins - Rosie Bolton and Elizabeth-Anne Haldane. Contributions from additional authors listed below
24.1. Introduction
24.2. Recent developments
24.3. Species identification (by Lu Allington-Jones)
24.3.1. Introduction
24.3.2. Macroscopic identification of fur
24.3.3. Microscopic identification of fur
24.3.4. Techniques for examining a hair
24.3.5. Caution when identifying fur
24.4. The treatment of fur in historic dress: Drawing on case histories from Zenzie Tinker Conservation (by Jamie Robinson, Rachel Rhodes and Zenzie Tinker)
24.4.1. Introduction
24.4.2. Pest management of fur in garments
24.4.3. Cleaning fur
24.4.4. Testing support adhesives, materials and application methods
24.4.5. Adhesive support and infill of fur
24.4.6. Display of fur in dress
24.4.7. Conclusion
References
Part 4: Preventive Conservation of Leather and Skin materials
25. Overview of Preventive Conservation for Leather and Skin Materials - Rosie Bolton and Arianne Panton
25.1. Introduction
25.1.1. Managing risk
25.2. Agents of deterioration
25.2.1. Physical forces
25.2.2. Thieves and vandals
25.2.3. Fire
25.2.4. Water
25.2.5. Pests
25.2.6. Pollutants
25.2.7. Light, ultraviolet and infrared
25.2.8. Incorrect relative humidity
25.2.9. Incorrect temperature
25.10. Dissociation
25.3. Recommended environmental parameters
References
25.4. Case studies
25.4.1. Caring for leather artefacts in Antarctica - Lizzie Meek, Sue Bassett and Stephanie Stott
25.4.2. Salvage Recovery of Zulu shields with limited resources and challenging conditions - Victoria J. Mcallister
25.4.3. Documenting and packing African shields during the University of Cambridge Museum of Archaeology and anthropology store moves project: an overview - Ayesha Fuentes
25.4.4. Making a handling and display support for a hide kayak - Shabnam Honarbakhsh and Heidi Swierenga
24.4.5. Managing photoshoots and filming in spaces with leather objects - Heather Murphy, Claire Fry and Sarah Lambarth
26. Insect pests and pest damage - David Pinniger and Jane Thompson-Webb
26.1. Materials at risk
26.2. Recognising pests and their damage
26.3. Pest prevention, monitoring and environment
26.4. Control of pests
26.5. Conclusion
References and further resources
27. Pesticides: Identification and safe handling - Arianne Panton and Marc Vermeulen
27.1. Introduction
27.2. Identifying pesticides using archive-based research and initial assessment
27.3. Identifying pesticides using analytical techniques and chemical testing
27.3.1. Detecting inorganic residues
27.3.2. Detecting organic residues
27.3.3. Choosing the right approach
27.4. Safety measures for handling and storage
27.5. Decontamination
References and bibliography
27.6. Case study: Exhibiting and lending pesticide-contaminated Bison robes: Challenges and solutions - Sebastian Kolberg
Index
Biography
Arianne Panton, ACR, is an accredited conservator specialising in leather, skin, and related materials, and Manager of Conservation and Research at the Leather Conservation Centre. She holds MSc and MA degrees in conservation from University College London (UCL) and her research focuses on modern, heavily finished twentieth-century leathers.
Rosie Bolton is Head of Centre at the Leather Conservation Centre (LCC), Leicester, UK. She is a conservator of leather and related materials, specialising in the material category during an ICON internship at the LCC. Research interests include historic manufacturing processes, reflection of cultural context in treatment and conservation pedagogy.
