The Riddle of the Image explores the materials and methods that lie behind the production of historic paintings. Spike Bucklow, who works as a research scientist and restorer of paintings, analyses some of the most well-known and important medieval works of art, as well as less familiar artworks, to throw new light on art production techniques that have been lost for centuries. By examining the science of the materials, as well as the techniques of medieval artists, he adds new aspects to our understanding and appreciation of these paintings, and of medieval art in general. The case studies include one of the most popular paintings in the National Gallery, London, and the altarpiece in front of which English monarchs were crowned for centuries. Many of the technical details presented here are published for the first time and some others have only been featured in exhibition catalogues and specialist academic papers. The author is internationally recognized for his work in the scientific examination of paintings and he also draws upon the work of other internationally recognized specialists. While intensive research into artists' materials and methods has been undertaken for several decades, this book is the first intended for a general audience that examines the subject in depth.