As I have been into 3 x 5 cards, I thought this from today's Washington Post was really interesting:
At the time of Nabokov's death, "The Original of Laura" also existed as a series of index cards, more than a hundred of them, in no obvious order. This Knopf edition consists of photographs of his miscellaneous handwritten cards, with a printed transcription of their text below, in a tentative order determined by Dmitri Nabokov.
The cards themselves may be detached from the book and, if desired, rearranged by the reader.
I wonder if the Levenger stationery catalog is going to see a sales spike.