When the manuscript was modified for Isabella Stuart, her arms were added to the border of several folios using gold and silver leaf as well as vermilion and carbon black. Her portrait was painted over that of the original patron kneeling before the Virgin and Child on fol. 20r, and St Catherine was added behind her. The saint’s blue mantle was painted with ultramarine, the same blue pigment used for the Virgin’s drapery during the original campaign. Soon afterwards, however, the patron’s originally large oval head dress was changed into a small ducal coronet. To hide the head dress, the front of St Catherine’s mantle was completed using azurite – the difference in pigments clearly revealed in the near-infrared image.
Azurite was also used for the Virgin’s robe and the background of the miniature added on fol. 28r for Margaret of Brittany in the 1450s. The green floor was painted with an organic colourant rather than the mineral green found in most of the images painted during the original campaign.
