WITH TWO ACCLAIMED solo shows in two years, Alexander Ross has become his own hard act to follow. Of course, given his highly developed imagery and the reception it has enjoyed, he could have coasted through this exhibition. But Ross is too smart to make the same painting over and over. So while he has not abandoned the tenets of his practice, he has pushed and distorted them in subtle but significant ways. The changes do not entirely work: This group of nine paintings and seven drawings (all Untitled, all except two from 2000) did not fully cohere, and there was an agitated buzz in the images, as if more had been packed into them than they could hold. But such passages of awkwardness are healthy for any artist, especially one who has derived great power from restraint and exactitude.

Ross's signature is a curiously detailed still life of an indeterminate blob, clearly made of green Plasticine, presented against a featureless sky blue or gray ground. Painted with photorealist attention to highlight and shadow, tactile stickiness and cool solidity, these figures are endowed with the weight of specific materiality, yet they decline meaning. This slippage between the tangible and the imaginary is the true subject of the paintings, and it lends them a strange poignancy—as if the hush of Dutch still life were reimagined by HAL or Deep Blue. Ross's rigorous, almost old-fashioned engagement with the object (he makes the clay models, photographs them, and paints from the photographs) endows the green things with an enigmatic, even totemic presence. Soberly precise yet utterly wacky, they suggest both the organic (cells, lichens, crystalline structures) and the artificial (pixels, plastics, maps) without committing themselves to either category.

In Ross's new work, the compositions and underlying references are the same, but he handles the paint differently now. His earlier brushwork was muted within the green shapes and invisible in the monochromatic backgrounds; the works were crisp, sensual, quiet. (The single 1999 painting included here made for an instructive comparison.) The more recent pieces feature strong, swirling strokes, systematized into terraced bands like topographical isobars. Color variation has been introduced into the backdrops, and the thickened brushwork integrates figure and ground, which had held separate before. The paintings still feel hermetically sealed, but their interior atmospheres have congealed: Instead of floating in cool thin air, the green shapes now seem sunk in a viscous and roiling element. Their sense of serene isolation is gone, or profoundly disrupted.

Adding to the overall busyness of the show were several experiments with shaped canvases: Some pieces had sliced-off corners, and one was hexagonal. A shaped canvas often signifies a step toward sculpture, as if the contents of the painting were spilling through a window frame, transgressing the picture-plane, but the impression here was more that the window frame had been cut at odd angles, affecting not the image but our access to it.

Ross keeps cataloguing the ways of representing agglomerations of matter, aka objects. His work is a flowchart of representational strategies (painting, drawing, sculpture, photography) and, in a way, he uses green blobs because they are convenient body doubles for imagination. The new topographical layering, wider palette, and polygonal canvases add more data to this already complex visual calculus. It will be interesting to see how Ross solves his next batch of self-assigned problems.

—Frances Richard