Simon Hantaï, who died in 2008, won renown for his revolutionary technique of pliage (folding), which saw him pleating and crumpling primed canvas, then painting it a solid, jewel-like block of color. Unfolded, the canvas became a matrix of echoing shapes, somewhat reminiscent of Matisse’s color fields and Pollock’s hugely scaled abstractions. To celebrate Hantaï, Gagosian unveils a series in which the artist renounced color: pliage canvases painted only in black. —E.C.