Why paint? In 1975, Artforum magazine posited the question to artists at a moment when enthusiasm for more contemporary approaches – from conceptual art to video – seemed to have pushed painting out of the vanguard. Lisson Gallery’s summer group show visits responses then and now as painters pushed the boundaries of what could be considered painting. Here, Polly Apfelbaum’s synthetic velvet and dye piece ‘Blue Joni’ takes painting off the stretcher and even off of the wall. (On view in Chelsea through August 9th).