Mark Bradford is back with more of the mixed media collage/decollage canvases that have made his reputation as a leading contemporary abstract artist, like this mixed media on canvas piece, ‘We May Be Running Out of a Past.’ His latest solo show at Chelsea’s Sikkema Jenkins & Co opened this evening, showcasing eight huge, vibrantly colored pieces that don’t evidence a new direction for the artist but do explain his popularity. (Through Dec 15th .)