Some artists make a virtue of variety. Ellsworth Kelly made a virtue of consistency, as can be seen in an exhibition of the final nine paintings the artist finished before he died in December 2015, on show at the Matthew Marks gallery (Ellsworth Kelly: Last Paintings, 5 May-24 June). Like much of Kelly’s work, the pictures revisit and expand on favourite motifs, including the rainbow-band Spectrum series he inaugurated in 1953. Next door, a concurrent show of 16 of his plant drawings made between 1949 and 2007 reveal his abiding interest in nature and form. Kelly’s commitment to his themes is “something that’s very important about his work,” says one of the gallery’s directors, Jacqueline Tran. “He was very consistent throughout, and collectors and museums don’t necessarily privilege one period over another.”