Marlow Moss, White, Black, Yellow and Blue, 1954© Tate St IvesIn life and in posterity, British artist Marlow Moss is the invisible woman. In photographs of her, for instance, with tightly cropped hair, dressed elegantly in jodhpurs with a pastel-coloured cravat tied high around her narrow throat, she uses clothes to conceal her gender. Today online, if you ever see her linear, abstract paintings and reliefs, you might mistake them for the work of the more revered Dutch pain...