` MEMLING 'S PORTRAITS ' The great Flemish painter Hans Memling -LRB- 1435-94 -RRB- is the subject of an exhibition of approximately 20 portraits by the artist and his school organized in collaboration with the Museo de Arte Thyssen-Bornemisza , Madrid , and the Groeningemuseum , Bruges , Belgium , two sites where it appeared before its final stop in New York .