To begin with, he told his sister over after dinner brandy and French pastries in her studio, because Books of Hours created and popular in the 15th century and early 16th century are more available than their predecessors, they are more often sold at auctions and by rare book dealers. Books of Hours are desirable by collectors and fetch increasingly high prices. For these reasons, they are sought by thieves.
Although medieval scribes inserted curses on thieves into manuscripts, perhaps due to skepticism about Hell or perhaps because the thieves did not read Latin, these curses appeared to have no deterring effect on contemporary thieves. Methods that manuscript thieves utilize, he explained, include false papers identifying them as distinguished scholars; bulky winter coats with large inside pockets; acquiring access to archives by making donations to a library or museum and in return being given unsupervised access to rare book collections; and seeking employment as cataloguers. Recently, in one of the larger known thefts, 145 manuscripts were stolen from an Italian library when the library was closed for renovation.
