Bernd Ribbeck splits the difference between spirit painting and heraldry. The portentously simple geometries of his India ink drawings and small acrylic paintings have knife-sharp edges and heady if unspecific symbolism. But the color is laid down as if in a diagram that can trust its viewer to take thought for deed—red ink painted in a watery wash that darkens at the edges, midnight blue paint rubbed away to reveal a layer of orange underneath. In one untitled drawing, two double sets of rings, blue over orange, are linked like the old magician’s trick, as an inverted heaven and earth. Each set is both triple and double, because the smaller, lighter ring is set inside its larger twin at a distance equal to the width of their lines, creating a space between them that reveals the lavender-stained sky but also overlaps the other set of rings. In an untitled painting of interlocking diamonds, planes of light shoot across from either side, changing the diamonds from orange to blue or adding bursts of yellow and gray. Maybe the difference Mr. Ribbeck is splitting is between René Magritte and Charles Demuth. (Through May 4, 2013)