Francesca Casadio joined the Art Institute of Chicago in July 2003 as the Museum's first A. W. Mellon Senior Conservation Scientist. Since January 2018 she is the Grainger Executive Director of Conservation and Science. With a PhD in Chemistry from the University of Milan, Italy, Casadio is also the founder and co-Director of the Northwestern University / Art Institute of Chicago Center for Scientific Studies in the Arts (NU-ACCESS). Her research interests are interdisciplinary studies mainly focused on artistic materials and practices of the 19th and 20th century.Katrien Keune is research scientist at the Rijksmuseum Amsterdam, Netherlands. She is responsible for the scientific research in the conservation studios. She also holds an appointment as Associate Professor of Chemistry at the University of Amsterdam (UvA) and contributes to the Netherlands Institute for Conservation, Art and Science (NICAS) at a scientific and organizational level. She received a PhD in chemistry from FOM Institute AMOLF, UvA. Her expertise lies in the ageing, deterioration and migration processes in oil paintings, especially related to pigment-binding medium interactions.  Petria Noble is senior paintings conservator and Head of Paintings Conservation at the Rijksmuseum in Amsterdam, a position she has held since 2014. Prior to this she worked for 18 years at the Mauritshuis in The Hague. As an expert in the material aspects and conservation of 17th-century Dutch paintings she has published widely in conservation and scientific journals. She is strong advocate for scientific investigations of paintings as a key to understanding changes in appearance. Her current research activities include the development and application of non-invasive imaging techniques for the study of late Rembrandt paintings.Annelies van Loon trained as a chemist and a paintings conservator, before specializing inthe materials analysis and ageing processes of Old Master Paintings. She received a PhD in chemistry from FOM Institute AMOLF/ University of Amsterdam on the topic of ‘Color changes and chemical reactivity in seventeenth-century oil paintings.’ From 2012 till 2016 she was project leader of the Science4Arts PAinT Project focusing on aspects of metal soaps and pigment-binder interactions. Currently she holds a position as paintings research scientist at the Rijksmuseum AmsterdamElla Hendriks is full Professor of Conservation and Restoration of Moveable Cultural Heritage at the University of Amsterdam. She holds a bachelor degree in art history (University of Manchester, UK), a post-graduate diploma in the conservation of easel paintings (Hamilton Kerr institute, University of Cambridge, UK) and a PhD in technical art history/conservation (University of Amsterdam). From 1987 to1999 she was Head of Conservation at the Frans Hals Museum in Haarlem, and from 1999-2016 Senior Paintings Conservator at the Van Gogh Museum in Amsterdam. Silvia A. Centeno is a Research Scientist at the Metropolitan Museum of Art where her main responsibilities include the investigation of artists’ materials and techniques and deterioration processes in paintings, photographs, and works of art on paper. She has published and lectured in a number of topics including soap deterioration in oil paintings, pigment- and platinum-based photographic processes, daguerreotypes, early lithographic inks, and nineteenth century and Renaissance paintings. She received a PhD in Chemistry from Universidad Nacional de La Plata, ArgentinaGillian Osmond is a paintings conservator at the Queensland Art Gallery/Gallery of Modern Art in Australia with 3 decades of industry experience. She has a longstanding interest in the technical examination of paintings and paint cross sections and has been studying incidences of zinc soaps in paintings for more than 15 years. In 2014 Gillian was awarded a PhD from the University of Queensland for her research on zinc oxide centred deterioration in artists’ oil paints and consequences for paintings.

• Foreword.- Preface.- List of Contributors.- 1 A Brief History of Metal Soaps in Paintings From a Conservation Perspective.- Part I Formation, Migration and Environmental Influences.- 2 Zinc Soaps: An Overview of Zinc Oxide Reactivity and Consequences of Soap Formation in Oil-Based Paintings.- 3 Towards a Complete Molecular Model for the Formation of Metal Soaps in Oil Paints.- 4 Understanding the Dynamics and Structure of Lead Soaps in Oil Paintings Using Multinuclear NMR.- 5 Historical Evolutions of Lead-Fat Formula from Antiquity to Modern Times: An Echo Between Pharmacy and Painting.- 6 Impact of Lead Soaps on the Formation of Age Craquelure.- 7 An Investigation into Metal Ions in Varnish Coatings.- 8 Ageing of Natural Resins in Presence of Pigments: Metal Soaps and Oxalates Formation.- 9 Factors Affecting the Reactivity of Zinc Oxide with Different Drying Oils: A Vibrational Spectroscopy Study.- Part II Innovative Approaches to the Characterization of Metal Soaps and Oxalates.- 10 Tracking Metal Oxalates and Carboxylates on Painting Surfaces by Non-Invasive Reflection Mid-FTIR Spectroscopy.- 11 Identification and Distribution of Metal Soaps and Oxalates in Oil and Tempera Paint Layers in 15th Century Altarpieces Using Synchrotron Radiation Techniques.- 12 Photoluminescence Micro-Imaging Sheds New Light on Phase Characterization in the Development of Metal Soaps in Historical Paintings.- 13  Physicochemistry of Pure Lead(II) Soaps: Crystal Structures, Solid and Liquid Mesophases, and Glass Phases: Crystallographic, Calorimetric and Pair Distribution Function Analysis.- Part III Characterization and Treatment.- 14 Taking Different Forms: Metal Soaps in Paintings, Diagnosis of Condition, and Issues for Treatment.- 15 Characterization and Removal of a Disfiguring Oxalate Crust on a Large Altarpiece by Hans Memling.- 16 The Development of an Aqueous Gel Testing Procedure for the Removal of Lead-Rich Salt Crusts on the Surface of Paintings by Giovanni Antonio Pellegrini (1675-1741) in the ‘Golden Room’ of the Mauritshuis.- 17 The Formation of Calcium Fatty Acid Salts in Oil Paint: Two Case Studies.- Part IV Case Studies in 19th and 20th Century Art: Artists and Paint Makers.- 18 Everything Old is New Again: Revisiting a Historical Symposium on Zinc Oxide Paint Films.- 19 Notes on Metal Soap Extenders in Modern Oil Paints: History, Use, Degradation, and Analysis.- 20 Delamination due to Zinc Soap Formation in an Oil Painting by Piet Mondrian (1872-1944): Conservation Issues and Possible Implications for Treatment.- 21 Paint Delamination as a Result of Zinc Soap Formation in an Early Mondrian Painting.- 22 Photometric Stereo by UV-Induced Fluorescence to Detect Protrusions on Georgia O’Keeffe’s Paintings.- 23 A Montparnasse Disease? Severe Manifestations of Metal Soaps in Paintings by Pierre Soulages from around 1959-1960 (Delaminating Oil Paint Layers, Medium Exudates, Discolourations).- 24 Seldom Black and White: The Works of Franz Kline.