Agnes Martin - The Islands, 1979. A series of twelve large square white acrylic and graphite paintings. Martin specified they should always be shown together, here they are in Room 9 at Tate Modern - image timeandtoast
Agnes Bernice Martin was a Canadian-American abstract painter, often referred to as a minimalist; Martin considered herself an abstract expressionist. She won a National Medal of Arts from the National Endowment for the Arts in 1998.