It is the fabulous balance of red and white squares in a Malevich gouache, or the glowing sheaves of fluorescent tubes in a Dan Flavin sculpture; it is Hélio Oiticica's black and
white rectangles swing - dancing across a painted board, and Sophie Taeuber - Arp's cross-stitch embroidery of circles and triangles holding hands, as it seems, with a big scarlet square.