Saunders D. Colour, Colour Measurement and Colour Change

Routledge, 2024. — 211 p.Colour, Colour Measurement and Colour Change, the first new book in the expanded Science for Conservators series, explains the science of colour, colour measurement and colour change for conservators in a clear and comprehensible way, elucidating the topic for those with no scientific background.
The book explains how and why we see colours and how colour and colour change can be measured, as well as clarifying why these would be done in a conservation context. It then examines the ways in which colour can change – such as darkening, yellowing, fading, blanching and patination – illustrating these in different types of cultural heritage materials, including metals, varnishes, plastics, textiles and paints. The final chapter explores how colour change can be reduced in different types of storage and display settings, and, in particular, what can be done to protect against damage by light, damp and pollutants.
This book is an invaluable introduction to all aspects of the science of colour in conservation. It is suitable for students in undergraduate and postgraduate conservation programmes, as well as being a useful reference guide for practising conservators.List of Illustrations
Foreword
Acknowledgements
Introduction
The Perception of Colour: How We See Colours
Electromagnetic Radiation
Colour Vision: the Role of the Eye
White Light
The Colour of Objects
Gloss and Scattering
Colour Vision: the Role of the Brain
Metamerism
Dark Adaptation
Colour Adaptation
Simultaneous Contrast
Successive Contrast
Colour Appearance Models
Additive and Subtractive Mixing
Colour Order Systems
The Origin of Colour: Why We See Colours
Chemical Causes of Colour
Absorption
Atoms and Absorption
Molecules and Absorption
Vibrational Levels
Rotational Levels
Transition Metal Colours
Colour From F–f Transitions
Charge Transfer Colours
The Colour of Metals
Band Gap Colours
Colour Centres
Absorption in Organic Molecules
Biopigments
Photoluminescence
Physical Causes of Colour
Structural Colours
Colour Due to Scattering
Particle Size
Combining Colours
The Measurement of Colour: How We Measure Colours
Colour Matching
Spectrometry
Spectrometers: Making Quantitative Measurements
Wavelength Calibration
Wavelength Resolution
Reflectance Or Transmittance Calibration
Geometry
Field of View
Types of Spectrometer
Spectroradiometry
Microspectrophotometry
Colorimetry
The CIE Xyz System
The CIE Lab System, Also Known as CIELAB
The CIE LCh System
Colorimeters
Reflectance Calibration
Geometry
Field of View
Colour Co-Ordinate Calculation
Illuminants and Observers
Ultraviolet Radiation
Colour Difference
Visual Comparisons
Spectrometric Comparisons
Colorimetric Comparisons
Just Visible Differences
Gloss
Yellowness and Whiteness Indices
Imaging Colorimetry and Spectrometry
Contact Or Non-Contact Measurement
Why Colours Change
Chemical Changes
Activation Energy
Light and Ultraviolet Radiation
Heat
Intrinsic Reactions
Extrinsic Reactions
Metals
Inorganic Compounds
Oxidation and Reduction
Pollutants
Carbon Dioxide
Organic Compounds
Oxidation
Hydrolysis
Cross-Linking
The Effect of Pollutants
Inherent Vice
Pigment–binder Interactions
Intrinsic Pollutants and Autocatalysis
Physical Changes
Physical Effects From Physical Changes
Physical Forces
Deposition and Movement
Physical Effects From Chemical Changes
How Colours Change
Lightening (Fading)
Darkening
Yellowing
Hue Shifts
Changes in Transparency
Changes in Gloss
Loss of Fluorescence
Significance and Acceptability of Colour Change
The Reversibility of Colour Change
Why We Measure Colour
Identification of Materials
Mapping the Presence of Materials Across an Object
Spectrometric Mapping
Colorimetric Mapping
Measuring and Monitoring Colour Change in Objects
Investigating and Predicting Colour Changes
Ranking Colour Change
Colorant Stability
Object Vulnerability
Microfade Testing (MFT)
Measuring the Colour of Light
Accuracy, Repeatability and Reproducibility
Accuracy
Repeatability
Reproducibility
Presenting Data
Mitigating Colour Change
Physical Forces
Light, Ultraviolet and Infrared
Water and Incorrect Relative Humidity
Incorrect Temperature
Pollutants
Oxygen-Free Atmospheres
References
Appendix A Derivation of CIE Lab and CIE LCh Data
Appendix B Derivation of the CIE 2000 Colour Difference (ΔE00)
Index