Almost to the time of his death in July at the age of sixty-eight, Ludwig Sander continued to explore intense, sometimes nerve-jangling color relationships within austere geometrical compositions. The format is derived from Neo-Plasticism—arrangements of rectangular and semirectangular planes of unmodulated color divided by thin black lines—but the effect owes much to Sander’s association with the New York School. He was a founding member of the 8th Street Club and part of the Abstract Expressionist milieu. There is a covert paradox in his art: hard-edge, geometric, carefully planned, it shares a dynamism, scale and insistent lyricism with Abstract Expressionism. For all their rigorous discipline of design, Sander’s paintings resonate with emotion.

His structures look as perfectly proportioned as the Parthenon—and they are just as deceptive. Instead of attaining a classic calm, the planes clench together with an almost tangible tension. The precise dovetailing of rectangles is idiosyncratic, full of jarring jumps in scale and discreet compromises with strict rectangularity. Sander’s paintings refuse to stay put. It is as if colors hammer at the edges of shapes to shift their conformation.

Most often the paintings contain one large squarish plane that is either bled to the canvas edge or surrounded by smaller bands of color. Our eyes can rest within this more spacious field. We may even imagine that it is situated at a different level of depth from the contiguous planes. Or, like gold in Byzantine mosaics, it can become an opening. By canny adjustments of color and shape, Sander did not allow the large squares to dominate or to recede permanently trom the canvas surface. Having studied with Hans Hofmann in Munich in 1931, and later having even translated one of his teacher’s texts into English, Sander knew how to use Hofmann’s “push-pull” theory. In the end, flatness prevails, and all the shapes form part of a taut, reverberating skin of color.

The same tenseness marks Sander’s colors. just as his rectangles are often ever so slightly askew, his colors ever so slightly avoid easy harmony. All but one ot the paintings in this show deploy variants of a single hue: the canvases are either all red, all green or all yellow (except, of course, for the black armature dividing color planes). In Arapahoe XVI, for example, a squarish field of fireman’s red blazes in the midst of wide vertical and horizontal bands of darker, less orangey reds. Sander constructed his color so that the brightest red is sustained like a metope between triglyphs on a supporting architrave. Yet the red’s ferocity is not diminished by its neat containment within a rectilinear format. Nor does color’s defiant elusiveness succumb to the apparent lucidity of form. Indeed the viewer finds it often difficult in Sander’s works to tell whether a band of a given color is actually the same on both sides when it is interrupted by a plane of another color. To us, the band might look like two separate rectangles, slightly different in tone. Color’s dissonance never abates, vibrancy never lulls into resolved harmony. Three paintings, all called Chickasaw, are battles of green. Grass green, pea green and olive shriek across the black grid lines.

He obviously exulted in his mastery of latency, of poise and potential. Sander’s exhibition included several pairs of paintings in which he repeated the same format while varying the colors. Genesee VII and Athabascan VIII, to name one pair, are identical in the disposition of their narrow black bands, but different in the way the planes that are formed by those bands are filled in with color. This exploration of familiar terrain does not, I think, signal any lack ot inventiveness. Rather, such paintings merely underscore Sander’s deft proportioning of color to meet the resonance of his geometry.

—Hayden Herrera