A product of the intersection of scholarship, fine printing, and connoisseurship, the leaf book has become, in many cases, the de facto means of accessing certain incunabula. Take, for example, the book produced by the Caxton Club in 1905 to honor its namesake, with a leaf from an incomplete copy of William Caxton's 1477 edition of The Canterbury Tales. The only complete copy to come up for sale in the last twenty-five years was in 1998; it contained leaves supplied from other copies, and the last text leaf was a facsimile. Nevertheless, it sold for $4.2 million. Likewise with a more recent book containing a leaf from the 1462 Fust and Schoeffer Bible, of which the last complete copy sold in 2002 for roughly half a million dollars.
These books not only provide entree into an exclusive strata of collecting, they also advance scholarship on the printers of these works and the society that influenced them. Very often we gain bibliographical insight into these works, as many will include a census of recorded copies. And finally, the books themselves have been produced by some of the best fine presses of the 20th century-Grabhorn Press, Plantin Press, John Henry Nash, and even Arion Press, to name but a few.