Think of Minimalism, the extremist art revolution of the 1960s, and what comes to mind is austere reduction and expressive denial. Does this make Post-Minimalism, which ever so slightly re-invests minimal forms and strategies with a personal touch, a counterrevolution? Not necessarily. The modifying tendency happened almost simultaneously, and many of its practitioners were friendly with the Minimalists. Furthermore, however much the avant-garde focused on what the Post-Minimalists were putting back in, the results to the rest of the world still seemed severe and streamlined.

Two current shows are devoted to the work of significant artists who took Minimalism as the starting point for idiosyncratic styles. Christopher Wilmarth, the Chatterton of Post-Minimalism who committed suicide at age 44 in 1987, is represented at Betty Cuningham by 10 sculptures made between 1969 and 1983 and a selection of drawings. Barry Le Va, counted as a pioneer of both minimal and conceptual art, has an overview of drawings at Mary Boone dating from 1967 to the present. Both artists not only squeeze personal expressivity out of starkly reduced means but make of reduction itself something richly ambiguous and imbued with poetry.

Given the circumstances of Wilmarth’s demise,it is sometimes hard to look at his work with a truly fresh eye. “Sonoma Corners” (1971), for instance, suspends an arc of etched glass on the wall from a steel cable that in turn forms a double square behind it. It can read as an almost fey essay in vulnerability – but is that a romantic reading, offered with hindsight?

Many of Wilmarth’s works balance opposing qualities of robustness and fragility, a dichotomy epitomized by his favorite combination of materials: steel and glass. While Minimalists preferred unmediated, basic, raw materials (bricks, steel plates, white-painted woodwork, felt), Wilmarth expressively milked his materials for all they were worth. He was a consummate craftsman who achieved a particular mastery in glass. The opposite of Dale Chihuly in tone and sensibility, he was nonetheless his equal in terms of an original understanding of glass. Equally theatrical in his way, Wilmarth was Cistercian to Mr. Chihuly’s Baroque.

Wilmarth himself might not approve of this comparison: He was opposed to curators and critics who focused on materials rather than the ends to which they are put. Ms. Cuningham, in her catalog essay, quotes him rejecting an invitation to participate in an exhibition devoted to artists working in glass: “I do not wish my art explored in material terms. The materials I use are a vehicle for poetic metaphor, the medium is light, and the subject is experience.”

“Gnomon’s Parade (Noon)” (1980) is from a series of nine stark, vertical pieces in steel and glass that take their title from the column on a sundial whose shadow determines the hour. A rectangle of etched glass is held in place, parallel to the wall, by two rods.A piece of steel bends twice, so that one plate is against the wall, the other at the bottom third of the glass.

Other times of day in this series gave rise to more lyrical convolutions of the metal, but noon has an almost bland simplicity. Its stark verticality makes it an enigmatic object. Without its title and some awareness of the poetic and spiritual ambitions of the artist, it could read as an abandoned architectural element, like a booth of some sort in a bank lobby.

Indeed, a chilly alienation in Wilmarth’s work runs counter to its poetic aspirations. In palette and structure alike, Wilmarths often resist empathy. Despite its title, the steel and glass “Invitation I”(1975-76) keeps the viewer at a distance; like a majority of Wilmarth’s sculptures, it forces a frontal view. His sculptures often operate as surfaces rather than forms, to be more pictorial than sculptural. An exception on this count, in the present show, is his blownglass piece,”When Winter on Forgotten Wood Moves Somber” (1979-80), a roughly oval, organic form with a single aperture that invites penetration and a sense of in-the-roundness, even though it is wall-mounted.

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You could call Barry Le Va the messy minimalist. His sprawling wall and floor installations, such as those seen in the inaugural show of the Danese Gallery’s new space in Chelsea last month, use harsh, austere, repeating forms. But his dense arrangements involve the viewer in ways alien to reductive art. His works on paper, exquisitely mounted at Mary Boone, betray a mind bent on complication as much as on resolution.

The earliest drawings, from the 1960s, are working sketches on squared paper, preparatory for installations. The magnificent, often paired later works, jumping up in scale and forward to 1989, are much more ends in themselves,while retaining a sense of the artist trying to work things out. All the titles suggest thought for sculpture.

Like Wilmarth, Mr. Le Va recalls Minimalism’s roots in a deeper,longer history of pared-down form – Brancusi is a common ancestor to both artists. Mr. Le Va also brings to mind the Russian Constructivists, although their progressive idealism is replaced by an existentialist sense of grappling with difficulties, what the painter Carroll Dunham described recently as “a scruffy, pessimistic point of view that skews his work away from any heroic or meditative readings.”

In a pair of drawings, “Study for Sculpture Occupying Two Areas” (1990), each about 4 feet wide, the artist uses cutout schematic shapes in inked carton that read a bit like military stripes. He builds up a sense of slippage, with these forms moving around the page looking for their correct location, through an expressive use of pentimenti. It gives the page an uneasy, contingent sense of a lived-in space,adding elements of doubt and struggle without resorting to expressionist gestures.

The two most streamlined drawings in the show, from 1974, have inked, stencil-like arcs and right angles on pale green sheets. These read like punch cards from a prehistoric computer or pianola roll. Something of their precisionist aesthetic comes across in Mr. Le Va’s most recent works, the “Tachycardia” series from 2005 of plan views for sculpture involving enigmatic plug- and socket-like shapes arranged with menacing insistence in a complex circuitry, seemingly rigorous according to their own logic.

Wilmarth through December 3 (541 W. 25th Street between Tenth and Eleventh Avenues, 212-242-2772). Le Va through December 17 (745 Fifth Avenue at 57th Street, 212-752-2929).