Op-art

Ernesto Mallard, resolute leader of Mexican Op-Art, has died, aged 89

After causing a sensation early in his career in the 1960s, the sculptor and visual artist retreated from the gallery scene, and was only recently re-acknowledged

Art marketpreview

Private View: our pick of November gallery shows

From a two-venue show of Albert Oehlen's abstract works in Paris to a Bridget Riley retrospective in Los Angeles, here are the gallery shows to see