Tundra, the last painting she did before she stopped working and left New York, opened entirely new ground for her. She knew it but decided not to pursue it. (By one account, she said she had painted all the pictures she needed to and younger painters would paint works subsequent to Tundra for her.) Tundra is a simple, almost inexplicable canvas. Its surface is divided by three lines into six tall rectangles. The pattern reminds you of a window, but the surface is closed. It suggests the heavy, white jade blankness of a snow sky. The lines that divide it are dominant at close range, but something very peculiar happens as you move back from this canvas. Because the horizontally brushed, grayish wash on the surface stops near but not against the lines, they seem to have halos around them. These halos actually swallow the lines at middle distance, leaving only their white ghosts. Even the ghosts disappear eventually.
—Kasha Linville in her piece Agnes Martin: An Appreciation
