Click the images below to see paintings from that period.		Other Information
Early Representational These paintings were done before the mature representational style emerged. They are organized similarly to the later paintings but lack the details and usually contain no staircases or porches done in the later style. The 1932 painting of a staircase may have been the first one he did.	Later Representational These paintings exemplify Mark's mature style and often include stairs and porches or other elements that convey similar diagonal or horizontal motion. The treatment of trees, bushes, and distant vistas is detailed and characteristically precise.	Transitional Mark did these paintings in the studio rather than outdoors. They reveal his growing dissatisfaction with representational painting, but are themselves still largely representational. They are abstract rather than non-objective and contain elements of his representational paintings.
Early Nonrepresentational When Mark finally discovered a style based on repeated identical units in 1958, he began producing paintings with no representational elements. These paintings were from the first expressions of emotional and spiritual themes. The units were originally derived from stairs and banisters, but evolved over the next few years into the form of the final unit, which remained unchanged from 1967 until he ceased painting in 1996. The evolution of the units may be seen in the folder called "Details."	Middle Nonrepresentational These paintings were done with the final unit and are organized as a hierarchy of units and filled-in clusters of units in a relatively flat space. At the beginning of this period, in about 1968, Mark switched from oil paints to acrylic paints, first painting backgrounds with acrylics and then painting the units with acrylics also. Early in this period, he completed some extremely large canvases, up to 100 inches in one dimension, but then returned to smaller canvases, usually 50 to 70 inches in each dimension.	Later Nonrepresentational From 1976 onwards, the units are organized into more varied shapes that relate to one another in compositions that are more fluid and incorporate more tonal and color variation. The movements are modulated by subtle tonal and color relations that also lend depth to the space.
1990s	Watercolors	Details