As modern artists stripped painting to its fundamentals, line — like color — became a subject in itself. Such minimalists as Sol LeWitt emphasized gridlike patterns, making art whose essential form was a diagram. Chip Allen, one of three abstract painters in Heiner Contemporary’s current show, once worked as a draftsman at the Sol LeWitt Foundation. But that influence is not conspicuous in “In Line/Out of Line,” which also features work by Katherine Sable and Camilo Sanin. The lines they render tend to be loose, even when they’re hard-edged.

Allen’s contribution, gouaches on paper that are simply tacked to the wall, follows strict patterns. But the Brooklyn-based artist also subverts them, with freehand brush strokes and splotchy imperfections, to reveal the action of painting. Despite the repeated matrices, these pictures are more human than mechanical.

Working in oil on linen, Sable constructs looser motifs, and the colors inside the lines seem more crucial than the perimeters. The local artist tends to use earth tones and grays but sometimes contrasts them with hot pinks and oranges. Such paintings as “It’s No Rainbow” hint at natural forms, perhaps honeycombs or reptilian scales. But Sable, like Allen, calls attention to the paint as much as the plan.

A Bogota native who received an MFA from the Maryland Institute College of Art in 2011 (and was included in Conner Contemporary’s “Academy 2011” show in July), Sanin takes a different approach. His lines are sharp and precise yet not regular. They twist and swing, as if one of Gene Davis’s stripe paintings had learned to tango. Sanin also paints boxes and wedges, generally in vivid colors and complex, shifting arrays. “From Here to There,” for example, moves from reds, oranges and maroons at the top to greens, blues and grays at the bottom. Sanin’s acrylics don’t reveal the medium; there’s not a smudge or drip to be seen. Yet his work is as vibrant as it is precise, with every impeccably tooled angle or block of color synchronized in an elaborate dance.

Stanley Agbontaen

In 2006, Stanley Agbontaen was one of six Nigerian painters whose work was exhibited in his homeland alongside that of two African American artists, Jacob Lawrence and Lois Mallou Jones. The connection makes sense, because all three are bold colorists, and Lawrence and especially Jones took inspiration from the art of Africa and its diaspora. Yet color is not the key to the work in Agbontaen’s exhibition at International Visions. The painter’s latest canvases do have a vivid palette, heavy on red and yellow, that moves away from the cooler hues of his previous District show. What is paramount in most of the pictures, however, is movement.

Agbontaen’s pieces include five constructed of carved and acrylic-painted wood, whose simple forms and traditional themes evoke African folk art. There are also a few paintings, such as “Black Morning,” that portray women in quiet moments. But most of these canvases depict dancers in motion or teeming street scenes. Rendered in thick oil paints, applied freely with a palette knife, the pictures border on the abstract. They freeze and fragment moments in the manner of cubism and futurism — and as combined by Marcel Duchamp in his once-controversial “Nude Descending a Staircase” (whose centennial year begins Sunday). Such exuberant canvases as “Spirit of the Festival” jangle with activity.

Things may be moving more slowly in Agbontaen’s street scenes, which illustrate the clogged arteries of Lagos, Nigeria, his current home town. Clearly, no one is approaching autobahn speeds on the packed thoroughfares shown in such paintings as “Heart of the City.” Lately, the painter has been climbing higher to craft street scenes that are simply blotches of color, conveying nothing more specific than urban bustle and the play of light and shadow. Pictures such as “Aerial View” contain no recognizable shapes, yet their clutter of daubs strongly suggests a cityscape. For Agbontaen, abstraction is not a path to a realm of pure form and color but another way of capturing the everyday vitality that surrounds him.

Jake Muirhead

Etchings are known for precise lines, while aquatints use a similar technique to produce more liquid-seeming images that resemble watercolor. Most of the works in “New Prints by Jake Muirhead,” on display at the Old Print Gallery, combine the two. The result is rich and subtle, achieving a looseness that seems incompatible with the process of etching a metal plate with acid. The artist also sometimes incorporates drypoint, whose effects appear closer to drawing; the show includes a drypoint “Jack-O-Lantern” that looks like a charcoal sketch.

A local printmaker and teacher, Muirhead often depicts traditional subjects. His show includes trees, flowers, fruit and female nudes. (One playful piece juxtaposes a naked woman with a bare slice of lemon.) Most of the prints are black-and-white or sepia-toned, but some are tinted with red and green. The latter hue highlights “Winter Tree,” while “Claws” chooses red to portray crustacean pincers. In color, the most complex print is “November,” in which red bleeds into green and then black.

Although Muirhead works in a centuries-old form, his prints have a contemporary outlook. His subjects include commonplace items that are battered or decayed, and the renderings seem equally weathered. “Oil Can” emerges from drips and smears, as if the print had been handled by a grimy-pawed mechanic (or, perhaps, Jackson Pollock). Showing an object that’s emerging from pictorial chaos is a classic technique, but Muirhead’s mastery makes it feel new.

Jenkins is a freelance writer.

In Line/Out of Line

On view through Jan. 14 at Heiner Contemporary, 1675 Wisconsin
Ave. NW; 202-338-0072; .

Stanley Agbontaen: A Celebration of Life

On view through Jan. 7 at International Visions, 2629 Connecticut Ave. NW; 202-234-5112;

New Prints by Jake Muirhead

On view through Jan. 23 at the Old Print Gallery, 1220 31st St. NW; 202-965-1818;