On April 28, 1958, hundreds of well-heeled Parisians lined up outside the Iris Clert Gallery at 3 Rue des Beaux-Arts, excited to see the newest works by an up-and-coming young artist, Yves Klein. There they were met by two Republican guards standing watch in front of a canopy whose shade was International Klein Blue, a vibrant cousin of cobalt that the artist had invented. While the guests waited to see the exhibit inside, they sipped blue cocktails made of gin and Cointreau, but upon entering, they found only a room with white walls, empty except for a bookshelf. The show was titled “The Specialization of Sensibility in the Raw Material State of Stabilized Pictorial Sensibility,” but it was also known simply as “The Void.”

It wasn’t until they returned home, bemused and annoyed, that the guests discovered the artist had left his mark in them: Their urine had been turned International Klein Blue. Klein couldn’t have been happier. His color had become a part of his guests, just as he wanted it to color the whole world. He thought it should be the color of the earth, and the color of the earth’s destruction—he once expressed a desire to paint an IKB atomic bomb. And beyond that destruction, there’s the state that Klein aspired to represent in all of his work: the void. Said literary critic Gaston Bachelard, an inspiration to the artist: “First there is nothing, then a deep nothing, and then there is a blue depth.” Even though Klein’s work is so firmly grounded in the terrestrial—earth, wind, fire, water—this blue depth, this void, renders the experience of seeing the Hirshhorn’s new Klein retrospective thoroughly otherworldly.

The title “Yves Klein: With the Void, Full Powers” comes from the inscription Albert Camus left in the guestbook of the 1958 exhibition, and it is the first retrospective of Klein’s work in the U.S. in more than 30 years. Through rarely seen works and artifacts, the Hirshhorn helps clarify the career of an artist who is often misunderstood as a Dadaist prankster—the empty room and the IKB urine speak to that misreading. But Klein took himself quite seriously. “The Void” wasn’t just about its irony—the dramatic set-up and the empty room. It was about understanding space and time, and Klein’s place among them—it was a metaphor for the future.

Klein is remembered for his conceptual work, such as the piece Zones of Immaterial Pictorial Sensibility, in which he sold empty space for gold. To complete the transaction, buyers had to burn their receipts, and Klein then threw half his profits into the Seine while two members of the Paris art community watched. But as sensational as these performance and conceptual pieces were, Klein was primarily a painter. He explored color in its purest form in his earliest series, Monochromes. These panels of single colors—of all shapes and shades—were initially rejected for their lack of composition. Klein published an exhibition catalogue for a show that did not exist, Peintures, with a blank space for an essay, and a series of pure colors printed for monochromes that never came to fruition.

Eventually, fed up with viewers looking at the monochromes in relation to each other instead of as individual works, Klein decided to focus on only one color: blue. His International Klein Blue, invented with the aid of a chemist, is a powerful gemstone of a shade, so energetic it seems to vibrate before the eye. That’s because Klein sought a way to bind pure pigment to the canvas in a way that did not diminish it, and his resin, as well as his color, are patented. In his first exhibition of blue monochromes, the artist created 11 identical panels of IKB, but sold them for different prices. One of the most striking works here is a re-creation of the 1958 and 1961 work “Pigment Pur Bleu,” in which a massive trough of IKB pigment dominates the room, like a sandbox of the void.

Klein moved beyond monochromes to what he called “Anthropometry”: the use of live models to spread his paint on his canvases. He thought paintbrushes were “too excessively psychological,” so he used rollers, and then his models’ flesh. Here, archival footage captures Klein’s pretty young things dipping their hands into buckets of IKB paint, covering their bodies with the pigment, and then pressing their stomachs and breasts to a canvas on the wall—or rolling around on a canvas on the floor. A brush hardly seems as psychological as the imprint of a nude human body, but Klein did not find it titillating, at least outwardly. He remained detached, preferring to dress formally, direct the models, and keep his hands clean. In 1960, he presented the making of a series of Anthropometries before an audience, set to the tune of his Monotone Symphony: twenty minutes of a single note and 20 minutes of silence. It was a sensation, and the symphony was later featured in the movie Mondo Cane, where it was purposefully distorted by the director. While watching to movie he suffered a heart attack—the first of three over the course of three weeks that would kill him at the age of 34.

But in the last few years of his life and short career, Klein generated a remarkable variety of work. First, there were the fire paintings—pieces of slow-burning cardboard that he attacked with a giant blowtorch and a hose, simultaneously. The cardboard captured the licks of flame and drips of water, as well as the wet imprint of the hosed-down models who would leave their body prints on the surface. Then there were “Cosmogonies,” paintings and reliefs that tried to harness the motion of the earth and of nature as Klein’s paintbrush. He would spray canvases with paint and take them to marshes, allowing grasses and rain and wind to leave their mark on his surface.

There were also sculptures, realized and unrealized. He had a plan for a “tactile sculpture,” in which the viewer would reach through holes in a dark box to feel the object inside. He planned to put a live nude model inside it, but backed off—“the police would have been on my back right away,” he wrote. The exhibit also includes rarely seen architectural plans for structures such as a fountain of both fire and water, as well as a roof formed by a stream of air so powerful it would deflect the elements.

Even more rare than these plans, though, is a work far more personal to Klein, not intended for public consumption. Klein was an arrogant man—he frequently wrote of his own genius—and one of the more telling artifacts in the exhibit is a piece of graph paper with the word “humility” written over and over, as though it were a punishment. But Klein was also a spiritual man, and in 1961 he made a pilgrimage to the Monastery of Saint Rita of Cascia with an offering. Rarely exhibited, the work is a Plexiglas box with three pigments—pink, IKB, and gold leaf, as well as several bars of gold that were proceeds from his sale of Immaterial Pictorial Sensibility, and an uncharacteristically humble message: “Grant me the grace that I may discover continually and regularly new things in art, each time more beautiful, even if, alas, I am not always worthy to be a tool for creating Great Beauty. May all that emerges from me be beautiful. So be it.”