The Menil Collection has been presenting from January 27th 2000 an exhibition of   works by the American abstraction expressionist   artist Willem   de Kooning (1904-1997) that  explores some of the many  procedures underlying   the artist's work and focuses on his shifts from   painting to drawing and drawing to painting.  Into   the late 1980s when de Kooning stopped  working   because of ill health, he regularly re-used and  recycled his art  works through various means of   tracing  and transferal.