“Untitled (Sculptural Study, Seventeen-part Right-angled Construction)” from the Glenstone show “Fred Sandback: Light, Space, Facts.” (Cathy Carver/Courtesy Glenstone /Copyright Fred Sandback Archive)

The word minimalism, often applied, doesn’t really fit the work of artist Fred Sandback. His sculptures, mere outlines of basic geometric forms made with acrylic yarn, are materially as minimal as anything made in the past half century. They are rough-edged, without the smoothness and polish of other minimalist artists. Nor are they neatly self-contained objects, and no curator will ever take out the Windex to keep them buffed to a high shine.

The Glenstone Museum in Potomac, an emerging powerhouse in the national arts scene founded by local philanthropists Mitchell and Emily Wei Rales, has opened a new exhibition of works by Sandback, the first show there since an exhibition devoted to the Swiss artistic duo Peter Fischli and David Weiss opened in May 2013. Near the 23,000-square-foot Gallery Building, which is displaying “Fred Sandback: Light, Space, Facts,” are construction fences, hiding from view the rapid progress being made on the 170,000-square-foot Thomas Phifer-designed new museum building, dubbed the Pavilions. When finished, sometime in 2017, Glenstone will rank in the top tier of privately endowed contemporary art institutions.

Meanwhile, it has devoted its entire 9,000 square feet of existing gallery space to an artist who used the most insignificant materials to create dizzying effects of space and geometry. The tall, wide-open and otherwise empty galleries are filled with the artist’s string sculptures and other works, including some made of metal and wood and others on paper. In one gallery, yarn defines a trapezoid that seems to be leaning against a wall; in another, six planes limned by yarn shot from floor to ceiling, arranged in a series of right angles; in yet another, 17 L-shaped forms in red are arrayed parallel to one another, like guillotine blades slotted into the floor with machine-made precision.

The work rattles what might be called the high and low extremes of human experience. It makes you keenly aware of the body as you move through museum space, exploring angles, and how patterns change depending on one’s vantage point. The 17 red-yarn parallel L-forms will push you toward the line on the wall where they vertically touch one wall of the gallery, and as you look down the line of right angles, a succession of rectangular forms is created by the overlapping string. They grow larger as they approach you, and it’s irresistible to set these forms in motion by moving up and down the spine of the work.

But they are ideal forms as well with the tautly stretched yarn (sometimes triple or quadruple thickness) serving more as a suggestion of their presence than a definition of their boundaries. Without the string, we would be unaware of the forms at all, but as you contemplate them, the string seems increasingly superfluous. This is the wonderful paradox of the work: It is insistently trifling and insistently perfect. Mathematics, naturally, comes to mind, especially the contrast between the simplicity of the formula that define lines and planes, and the infinity of the results. A child who can think in three dimensions can define a plane, say z=3, and with that rudimentary equation he has created something that slices through planets and galaxies to the unknown limits of existence.

A 2000 photo of Fred Sandback at Annemarie Verna Galerie in Zurich. (Thomas Cugini/Courtesy Fred Sandback Estate)

Sandback’s sculptural forms are often open-ended on one side, either where they meet the ceiling, or intentionally left open, as in “Untitled (Scuptural Study, Corner Construction),” 1981/2009, in which two squared-off U-shaped forms in a corner look like recessed picture frames missing their top arms. The missing top lines aren’t, in fact, missed at all; rather, one senses the impress of the edge of an infinite form, with the brain filling in what isn’t explicitly present.

Sandback, an American artist who died in 2003, was interested in philosophy and music, and had a passion for dulcimers, archery and making bows. A single taut string — in music referred to as a monochord — can be used to define the entire musical scale; and a tight string, drawn back with great force, can propel objects with deadly speed. The austerity and precision of Sandback’s art will suggest musical cues, perhaps more Anton Webern than Philip Glass, as well as a sense of rarefied violence. An untitled 2000 work made from fiberboard looks like it bears the marks of a radial-arm saw drawn repeated over a block of wood at different angles. Even the most mystically evanescent of his string sculptures suggests blade-like sharpness, a slice through the material stuff of the world, as if to lay out an infinitesimally thin cross section under the celestial microscope.

But the analogy with music is also a matter of highlighting the gulf between ideal and actual perception. If you stand at one end of an axis of Sandback’s string lines, you might think that all the strings would merge into a single string when perfectly aligned. And so they do if you shut one eye. If you keep both eyes open, you’ll have double vision and the strings will be a blur.

Few artists are better at demonstrating the amount of work that the brain does unconsciously, even in the simplest acts of looking. The three-dimensionality of Sandback’s forms depend in part on our having two eyes and depth perception and the ability to finish the form in the mind.

And once you’ve finished them, once the rather crude string has suggested the ideal form, you may find yourself impatient with the physicality of the yarn. The ideal encounter, perhaps, would allow the visitor to remove the cords entirely once the form is perceived, so that after walking through the galleries you would have in your hand a small clump of cheap thread, and in your thoughts an ideal world of pure geometry. Plato would smile benignantly on your progress, from the particulars of something sketched in the real world to the transcendence of pure form.

But it took a lot of moving about, looking through, passing in between, to get there. And when you leave the galleries, the meaningfulness of the experience begins to evaporate — rather like the memory of music is essential to our pleasure, yet always craves refreshing by hearing the music again. We are locked in the world, and there are no purely abstract, perfect pleasures.

The exhibition is an absorbing and smart successor to the previous Glenstone show, devoted to the Swiss duo Fischli and Weiss. The Fischli and Weiss survey was full of raw clay, small, almost hand-size sculptures, humorous, provocative and Rabelasian in their earthiness. Sandback has his own sense of humor, but it’s hard to imagine a stronger aesthetic contrast between the two shows. Taken together, their juxtaposition suggests a wry and strategic curatorial sensibility.

Fred Sandback: Light, Space, Facts is on view at Glenstone until summer 2016. For more information, including hours and reservations, go to www.glenstone.org.