Bar - British Series 671 - Making a Medieval Stained Glass Window: An archaeometric study of technology and production

Medieval stained glass windows are relatively untapped sources of information about medieval technology and production because their architectural context usually prohibits sampling for chemical analysis. This volume presents a comprehensive study of York Minster’s Great East Window (1405-1408), investigating glass-making technology and provenance, and glass-painting craft organisation. Chemical analysis relies upon established methods of elemental and isotope-ratio analysis and development of an in-situ technique, handheld/portable x-ray fluorescence (pXRF). The book also brings together historical documentation, art historical information, and meta-analysis of legacy data. Concepts borrowed from archaeological and pedagogical studies, including chaîne opèratoire, technological choice, apprenticeship and batch theory, and production models from the automobile industry, provide a new lens through which to interpret the data. Findings regard long-term relationships between York Minster and glass suppliers, the level of sophistication exhibited by medieval glassmakers, and detailed insights into the window workshop, including identification of work by different craftsmen. Cover Title page Copyright Of Related Interest Acknowledgements Contents List of figures List of tables Abstract 1. Introduction 1.1 The Great East Window of York Minster 1.1.1 Glass-making technology and acquisition 1.1.2 The organisation of stained glass window production 1.2 Challenges in the study of medieval stained glass by materials science methods 1.2.1 Trace element methodology 1.2.2 Interference of lead cames 1.3 Overview 2. The Great East Window of York Minster 2.1 York in 1400 2.2 Construction of the window 2.3 York Minster Revealed 2.3.1 Composition, Corrosion and Origins of Medieval Window Glass: The Cardiff-York project 2.3.1.1 Samples from the project 2.4 Summary: A window of opportunity 3. Glass-making in the medieval period 3.1 Medieval treatises on glass-making 3.2 The chemical composition of medieval forest glass 3.2.1 Factors affecting the chemical composition of medieval glass 3.2.2 Transition to high lime, low alkali (HLLA) glass 3.3 Colour technology 3.3.1 Control over the furnace and redox conditions 3.3.2 Addition of colourants to the melt 3.3.3 Flashed glass and other composite glasses 3.4 Possible sources for the GEW glass 3.5 Regional trends in glass composition: Synthesis of previous analytical work on medieval European glass 3.6 The GEW and glass-making technology 4. Medieval glass-painting 4.1 Medieval treatises on glass-painting 4.2 Cartoons and glazing tables 4.3 Medieval craft guilds and glass-painting 4.4 Workshop practice 4.5 A multidisciplinary approach 5. Problems and possibilities: Using handheld pXRF to study medieval stained glass windows 5.1 An introduction to handheld pXRF 5.1.1 The basic principles behind XRF analysis 5.1.2 Handheld (portable) XRF: Practical considerations 5.1.2.1 The sample material 5.1.2.2 Instrumental settings 5.1.2.3 Quantification 5.1.2.4 Performance, problems and potential 5.2 Handheld pXRF in archaeology and cultural heritage 5.2.1 The English Heritage Historic Window Glass project 5.3 Surface conditions of medieval stained glass 5.3.1 Composition and corrosion of medieval stained glass 5.3.2 Decorative details: grisaille and silver stain 5.3.2.1 Grisaille 5.3.2.2 Silver stain 5.4 The interference of lead cames 5.5 Developing a methodology for the study of medieval stained glass windows by handheld pXRF 6. Methods 6.1 Materials and sampling 6.1.1 Great East Window, York Minster 6.1.2 The Cardiff-York project: Data and samples 6.1.2.1 Little Birches Wolseley, Staffordshire 6.1.2.2 St William Window, York Minster 6.2 Analytical methods 6.2.1 Handheld pXRF analyses 6.2.2 Electron microprobe analyses 6.2.3 OM and SEM imaging 6.2.4 Laser ablation ICP-MS analyses 6.2.5 Isotope ratio analyses 6.2.6 Development of glass calibration standards 6.3 Tests for methodological development 6.3.1 Elements affected by surface conditions 6.3.2 The interference of lead cames on in situ analysis 6.4 Identification of glass batches 6.5 Summary of the research methods 7. Performance of handheld pXRF in the analysis of medieval stained glass 7.1 Trace element methodology 7.1.1 pXRF performance on standards and medieval glass 7.1.2 Deterioration and the depth of analysis 7.1.3 Trace elements in medieval forest glass 7.2 Bypassing the interference of lead cames 7.2.1 Comparison of in situ and test stand analyses by pXRF 7.2.2 Analysis of glass at increasing distances 7.2.3 Comparison of empirical calibrations 7.2.4 Factors affecting the measured intensity with increased working distance 7.2.5 Development of an attachment for in situ window analysis, the WindoLyzer 5 7.2.6 Health & Safety 7.3 Summary 8. Chemical characterisation of the Great East Window glass 8.1 Characterising major glass types 8.1.1 Identification of original and non-original glass 8.2 Glass original to the window 8.2.1 The original white glass 8.2.1.1 Comparison with Staffordshire glass 8.2.2 The original blue and red glass 8.2.2.1 Blue colour: Comparison with Gratuze cobalt ores 8.2.2.2 Red glass: Comparison with Kunicki-Goldfinger et al. (2014) 8.2.3 The original green and yellow glass 8.2.4 The original manganese-coloured glass 8.2.5 Original HLLA glass? 8.3 Non-original medieval forest glass 8.3.1 Non-original white forest glass (potash-lime) 8.3.2 Non-original coloured forest glass (potash-lime) 8.3.3 Non-original HLLA glass 8.4 Summary of the compositional results 9. Original white glass batches and their distribution in the window 9.1 Identification of batches using compositional data 9.1.1 Panel-by-panel identification 9.1.2 The cross-window approach 9.1.3 Significance of clusters 9.2 Distribution of batches across the panels 9.2.1 Row 1 panels (1e, 1h, 1j) 9.2.2 Panel 3b 9.2.3 Panel 10c 9.2.4 Panel 10e 9.2.5 Panel 10h 9.2.6 Panel 15a 9.2.7 Panel 15b 9.2.8 Panel 15f 9.2.9 Panel 15g 9.2.10 Panel 15h 9.3 Summary 10. Recipes and procurement of the GEW glass 10.1 White glass 10.1.1 Provenance 10.1.1.1 Consignments of white glass 10.1.2 Customer-supplier relationship 10.2 Coloured glass 10.2.1 Regional provenance 10.2.2 Glass-making technology 10.2.3 Importation of European glass to England 10.3 HLLA glass 10.4 Summary 11. Glass-painting and the organisation of production in John Thornton’s workshop 11.1 The long-term progress of the glazing project 11.2 The glazing table as a workspace 11.3 The division of labour in the production of panels 11.3.1 Taylorism-Fordism: the assembly line model 11.3.2 Toyotism: the cellular model 11.3.3 Panel production 11.4 Workshop organisation 11.4.1 The work of John Thornton? 11.5 Summary 12. Conclusions 12.1 Development of a methodology 12.1.1 The trace element methodology 12.1.2 The WindoLyzer 5 12.2 Glass-making and procurement of the glass 12.3 The organisation of production in Thornton’s workshop 12.4 A window to the past Appendix A. The Great East Window of York Minster: Supplementary materials and sampling A.1 The contract for the glazing of the GEW A.1.1 James Torre, English version A.1.2 Matthew Hutton (English translation) A.2 Timeline of the GEW A.3 Images and sampling Appendix B. Analytical methods: Supplementary information B.1 EPMA-WDS channels and crystals B.2 Empirical calibrations for the pXRF analyses Appendix C. UCL Reference Glasses AD1, AD2 and AD3, based on medieval forest glass compositions C.1 Preparation of the standards C.2 Elemental analysis by EPMA-WDS and LA-ICP-MS C.3 Recommended compositions based on elemental analysis Appendix D. Results of the chemical analyses Appendix E. Identification of batches E.1 Panel 1e E.2 Panel 1h E.3 Panel 1j E.4 Panel 3b E.5 Panel 10c E.6 Panel 10e E.7 Panel 10h E.8 Panel 15a E.9 Panel 15b E.10 Panel 15f E.11 Panel 15g E.12 Panel 15h References "Medieval stained glass windows are relatively untapped sources of information about medieval technology and production, because their architectural context usually prohibits sampling for chemical analysis. This volume presents a comprehensive study of York Minster?s Great East Window (1405-1408), investigating glass-making technology and provenance, and glass-painting craft organisation. Chemical analysis relies upon established methods of elemental and isotope-ratio analysis, and development of an in-situ technique, handheld/portable x-ray fluorescence (pXRF). This volume also brings together historical documentation, art historical information, and meta-analysis of legacy data. Concepts borrowed from archaeological and pedagogical studies, including chaîne opèratoire, technological choice, apprenticeship and batch theory, and production models from the automobile industry, provide a new lens through which to interpret the data. Findings regard long-term relationships between York Minster and glass suppliers, the level of sophistication exhibited by medieval glass-makers, and detailed insights into the window workshop, including identification of work by different craftsmen."