than a thousand illuminated books before his death. According to Thomas Kren, Philip's "library was an expression of the man as a Christian prince, and an embodiment of the state – his politics and authority, his learning and piety". Because of his patronage the manuscript industry in the Lowlands grew so that it dominated Europe for several generations. The Burgundian book-collecting tradition passed to Philip's son and his wife, Charles the Bold and Margaret of York; his granddaughter Mary of Burgundy and her husband Maximilian I; and to his son-in-law, Edward IV, who was an avid collector of Flemish manuscripts. The libraries left by Philip and Edward IV formed the nucleus from which sprang the Royal Library of Belgium and the English Royal Library. Netherlandish illuminators had an important export market, designing many works specifically for the English market. Following a decline in domestic patronage after Charles the Bold died in 1477, the export market became more important. Illuminators responded to differences in taste by producing more lavish and extravagantly decorated works tailored for foreign elites, including Edward IV of England, James IV of Scotland and Eleanor of Viseu. There was considerable overlap between panel painting and illumination; van Eyck, van der Weyden, Christus and other painters designed manuscript miniatures. In addition, miniaturists would borrow motifs and ideas from panel paintings; Campin's work was often used as a source in this way, for example in the "Hours of Raoul d'Ailly". Commissions were often shared between several masters, with junior painters or specialists assisting, especially with details such as the border decorations, these last often done by women. The masters rarely signed their work, making attribution difficult; the identities of some of the more significant illuminators are lost. Netherlandish artists found increasingly inventive ways to highlight and differentiate their work from manuscripts from surrounding countries; such techniques included designing elaborate page borders and devising ways to relate scale and space. They explored the interplay between the three essential components of a manuscript: border, miniature and text. An example is the Nassau book of hours (c. 1467–80) by the Vienna Master of Mary of Burgundy, in which the borders are decorated with large illusionistic flowers and insects. These elements achieved their effect by being broadly painted, as if scattered across the gilded surface of the miniatures. This technique was continued by, among others, the Flemish Master of James IV of Scotland (possibly