"Since the beginning of 2001, I draw in small notebooks 11 cm X 15 cm
(approximately), always with a ball point pen, always on same paper, always in
black. I contrained myself never to tear a page off, what is done... is done. I
put the date at the beginning and the end of each notebook. Each day (or almost)
I spend one hour or two drawing in these notebooks. At this day, I made
approximately 450 pages distributed in 12 notebooks."
[translation courtesy of Boing Boing]
Without being able to understand the French, I can only marvel at the almost obsessive nature required to generate this output.