The intention here is to elucidate Rothko's achievement in terms of the paintings themselves. The danger of the literary approach to Rothko is not that it necessarily mistakes his intentions, but that it diverts attention from the primary expression of his intelligence, his paintings.

From 1950 all Rothko's painting, with the exception of the pictures connected with the Seagram mural commission of 1958, and the last so-called black and grey paintings of 1969—70, observes a similar format. A part of Rothko's purpose seems to have been to make his authorship immediately recognizable. Typically, rectangles of colour, more or less regular in shape, exist within areas of ground colour. Their sides generally extend fairly close to the edge of the canvas, leaving a margin of ground colour on either side. The height of the rectangles and their internal relationships vary considerably from painting to painting, but their symmetry is almost invariable. Rothko avoids the use of shapes that would surprise by their irregularity or unusual positioning, and does not draw attention to the edge of the canvas, as he would if he allowed any of the internal colour shapes to break their symmetry in a single place and spread to the edge of the picture. Rothko's minimal involvement with shape, and particularly his avoidance of any obliqueness in the placing of the shapes, means that his pictures relate very directly to the spectator. They answer back in the way Piero della Francesca's Baptism or Resurrection do, because of the frontality of the figure of Christ. That is not to say that in either artist's work immediate contact leads more quickly to fuller revelation. The creation of this kind of response is the artist's method of holding the spectator's attention, of drawing him into the picture and inviting him to consider it in detail.

Rothko is not, in general, involved with shape for its own sake, nor is he primarily concerned with line, nor at all with perspective. He does not want formal innovation in his pictures to be seen as something important in itself. Against this negative summary of characteristics can be put his positive concern with gradation of colour and tone, interest in texture and often brushwork, and in the formation of local variations of space. All these concerns relate to the detail of the pictures. Rothko himself described his purpose as ‘the simple expression of the complex thought’. Simplicity of expression is indeed evident in the layout of the paintings, but his complexity of thought has a counterpart in the complexity of detail in the pictures. The simple format, the self-enforced limitation in Rothko's pictorial language, is one of the main sources of his freedom. His basic form is severe, and as soon as one becomes familiar with his art, expected. It is an undistracting framework within which problems of light and colour are resolved.