In 1972 McKnight left Time, summered on the Greek island of Mykonos, and commenced painting in earnest.
[2] McKnight was commissioned by the city of Kobe, Japan to create a series of paintings to act as the centerpiece for its tricentennial celebration.
[3] In 1994 he was commissioned by the White House to paint the first of three images for President Bill Clinton’s official Christmas card.
[4][5] One of these, "White House Red Room", was used as the cover of a Lands' End catalog, which sold both the art and the original as one of the Christmas gift items.
McKnight's work is represented in the permanent collection of New York's Metropolitan Museum of Art, as well as in the Smithsonian Institution.