Lynn F. Jacobs is Distinguished Professor at the University of Arkansas. She has published numerous articles as well as three books: Early Netherlandish Carved Altarpieces, 1380-1550: Medieval Tastes and Mass Marketing; Opening Doors: The Early Netherlandish Triptych Reinterpreted; and Thresholds and Boundaries: Liminality in Netherlandish Art.

• List of Illustrations, Acknowledgements, Introduction, 1. Framed Boundaries: Conrad von Soest and Early Fifteenth-Century Westphalian Triptychs, 2. Transparent Boundaries: Colour on the Exterior of German Fifteenth-Century Triptychs, 3. Regional Boundaries: Rogier van der Weyden's Columba Altarpiece and Cross-Influences Between the Netherlands and Cologne, 4. Spiritual Boundaries: The Master of the St. Bartholomew Altarpiece and the Border between Reality and Eternity, 5. Coda: The Triptych in the Age of Dürer, Bibliography, Index.

Lynn F. Jacobs is Distinguished Professor at the University of Arkansas. She has published numerous articles as well as three books: Early Netherlandish Carved Altarpieces, 1380-1550: Medieval Tastes and Mass Marketing; Opening Doors: The Early Netherlandish Triptych Reinterpreted; and Thresholds and Boundaries: Liminality in Netherlandish Art.

• List of Illustrations, Acknowledgements, Introduction, 1. Framed Boundaries: Conrad von Soest and Early Fifteenth-Century Westphalian Triptychs, 2. Transparent Boundaries: Colour on the Exterior of German Fifteenth-Century Triptychs, 3. Regional Boundaries: Rogier van der Weyden's Columba Altarpiece and Cross-Influences Between the Netherlands and Cologne, 4. Spiritual Boundaries: The Master of the St. Bartholomew Altarpiece and the Border between Reality and Eternity, 5. Coda: The Triptych in the Age of Dürer, Bibliography, Index.

Lynn F. Jacobs is Distinguished Professor at the University of Arkansas. She has published numerous articles as well as three books: Early Netherlandish Carved Altarpieces, 1380-1550: Medieval Tastes and Mass Marketing; Opening Doors: The Early Netherlandish Triptych Reinterpreted; and Thresholds and Boundaries: Liminality in Netherlandish Art.

• List of Illustrations, Acknowledgements, Introduction, 1. Framed Boundaries: Conrad von Soest and Early Fifteenth-Century Westphalian Triptychs, 2. Transparent Boundaries: Colour on the Exterior of German Fifteenth-Century Triptychs, 3. Regional Boundaries: Rogier van der Weyden's Columba Altarpiece and Cross-Influences Between the Netherlands and Cologne, 4. Spiritual Boundaries: The Master of the St. Bartholomew Altarpiece and the Border between Reality and Eternity, 5. Coda: The Triptych in the Age of Dürer, Bibliography, Index.