Since Paul Coreman's ground-breaking L'Agneau mystique au laboratoire in 1953, the Ghent Altarpiece, masterwork of the Van Eyck brothers, has been a major focus of research at the Royal Institute for Cultural Heritage (KIK-IRPA, Brussels). Some sixty years later, in the wake of a new conservation campaign in which KIK-IRPA is again playing the leading role, the art of Hubert and Jan van Eyck took centre stage at the Symposium XVIII for the Study of Underdrawing and Technology in Painting (Brussels, 19-21 September 2012). The event was organised by the KIK-IRPA and the Centre for the Study of the Flemish Primitives in collaboration with the Laboratoire d'etude des oeuvres d'art par des methodes scientifiques (Universite catholique de Louvain-la-Neuve), and Illuminare - Centre for the Study of Medieval Art (Katholieke Universiteit Leuven). The Ghent Altarpiece and the oeuvre of Jan van Eyck continue to captivate modern viewers and still arouse tremendous interest among art historians. The fascination with Eyckian art, with all its dazzling illusionistic effects and iconographic finesse, is every bit as fresh and challenging as it was six centuries ago. During three days of presentations and intense discussions, eminent specialists from all over the world attempted to fanthom the secrets of Van Eyck's success. They debated the issues from a variety of different standpoints, and shed new light on thorny topics such as attribution, iconography and painting technique. This book captures the variety of thirty-seven papers presented at the symposium and provides state-of-the-art knowledge on one of the most significant painters of all time. It should be read in conjunction with the widely acclaimed website "Closer to Van Eyck", which offers the scientific imagery of the Ghent Altarpiece in glorious high resolution.