The artist Xie Molin was born in Wenzhou in 1979. Unlike most painters, he does not paint with his own hands. He built a machine instead, and treats the machine as his hand — moving it along the X, Y and Z axes, fitted with different serrated blades, to explore the open-ended possibilities among pigment, space, pattern and visual language. His studio in Beijing looks nothing like most artists'.

There is no easel, no brushes, no palette. In their place stands a massive machine at one end of the room, taking up most of the floor space — the studio reads less like a painter's atelier than a factory workshop. Burning canvases with fire, boiling oil pastels down to liquid, collaging drawings out of wet toilet paper: even as a student at the Central Academy of Fine Arts, Xie was restless, working through one unlikely material and format after another. His solo exhibition "Vertical Lines" opened at Beijing Commune in September and, interrupted more than once by the pandemic, has continued to run ever since.

The works on view belong to several series made over the past three years in close collaboration with his machine. We recently reached the artist, who was sheltering at home, to talk about how he works. Before he lays down any oil paint, Xie runs the machine through a pencil version of the composition first, sketching out the color bands it will later paint. In 2019 he completed a new machine, more precise than any he had built before.

Some of the works at Beijing Commune were made on this new machine.

"The machine is a three-axis CNC device — X, Y and Z, just like the Cartesian coordinates from middle-school math." Many of his pieces carry the words "Suspended Blade" in their titles, a reference to how the machine actually moves when it paints: the serrated blade travels in a straight line without ever touching the work surface, hovering just above it like a blade in midair. "I hang a long, very sharp blade off the Z axis," he said. "It shaves across the pigment the way a razor shaves skin. There's a gap between the canvas and the blade, so the blade only touches the paint, never the canvas itself."

The advantage of the machine, he told us, is that it holds that gap constant. "Our hands shake. They're not stable enough, not precise enough. The machine amplifies what a hand can do." The relationship hasn't always gone smoothly. He once built a machine that painted in a rotating circular motion — months of back-and-forth with a factory to get it made — only to discover that its blade kept leaving a ridge of built-up pigment on the finished surface, no matter how he adjusted it.

In the end he gave up on it. The machine had cost him a hundred thousand yuan to build; he sold it for scrap, for a thousand. A diamond-patterned painting on view, its lower half seemingly liquefied, is the product of years of trial and error.

Why a diamond shape for the "liquefied" pattern? He arrived at it only after trying triangles, ovals, and other structures. "The pattern above and the pattern below end up tightly linked, and there's more room for variation," Xie said. He painted this diamond-and-liquid piece — yellow, green, yellow, blue, white — during the pandemic, using the colors as an abstract stand-in for the tissues of the human body.

"Blue is veins, red is blood, yellow might be fat or interstitial fluid, white is bone." The liquefied effect makes the texture and variation of the "tissue" hard to look away from, and the uncontrollable quality of that flow, he suggested, mirrors something of his own state of mind. Painting by machine comes with its own hazards, mostly in the form of software accidents.

But an accident can sometimes turn into a story. The "Dunhuang" series in his new show grew out of one such mistake, made while he was working on the diamond paintings.

"I accidentally let the suspended blade touch the canvas, and it cut right through the composition I'd already made." Not wanting to waste the pigment, and reasoning that the painting was ruined anyway, he decided to experiment.

"I scraped a blade back and forth across the canvas by hand, just to see what else was there to find," he said. That back-and-forth, done by hand rather than machine, is what gave him the idea for the new series. For all that the machine does the actual painting, the preparation that precedes it is anything but simple.

The colors have to be mixed, a sketch drawn up on the computer, the machine's path translated into code the device can follow. Mixing the paint alone can eat up enormous amounts of time. "In 'Vertical Lines,' for instance, there might be more than two hundred colors. A lot of the combinations and gradations are very fine, and every single color is mixed by hand — that's not something the machine can do."

Once the paint is mixed, he squeezes it onto the canvas by hand, one tube at a time. The whole preparatory process is so long and so tedious that it starts to sound less like painting than a kind of discipline.

"Waiting, and emptiness, are part of the work too." His break from convention actually began back in college.

"From elementary school on, I went through a very rigorous, systematic training in Western painting back in Wenzhou — drawing, color, sketching — all the way through to getting into the CAFA-affiliated high school and then the mural painting department at CAFA. That system stayed with me for years." But drawing models and painting landscapes all day, he came to feel, was never the kind of work he actually wanted to be doing.

"I was anxious and adrift for a long time back then." It was while working as a teacher's studio assistant that he first noticed something odd about acrylic paint — a discovery that gave him a thread to follow.

"Whatever acrylic was left over in the plastic bucket after I finished painting would dry fast — by the next day it had become a skin you could peel off. I peeled one off and found the underside was glossy. I thought, why not just use the paint as if it were plastic," he said. He began casting acrylic skins on wax, then pouring thin, watery paint over the surface; the water made the dried acrylic blister and buckle, forming mottled, leopard-print patterns of color.

He wanted to use that unusual texture to imitate the skin of an animal that didn't exist. Having gotten a taste for working against the grain, Xie also tried drawing with a lit blowtorch, using its scorch and smoke to suggest feathers on a bird falling in flames. In his dorm room, he once melted oil pastels in a pot and used them to copy Jin Shangyi's painting "Tajik Bride" onto an aluminum sheet.

Once it was finished, he took the blowtorch to the back of the panel; the oil pastel melted again, and the bride's face dissolved into a blur. For his graduation project, he collaged a drawing of a sinking naval submarine out of wet toilet paper laid onto sheet metal, using water to control how much the metal rusted beneath it — and with it, the tonal range of the drawing. He made the work at home in Wenzhou, in the middle of the SARS outbreak, an odd echo of the pandemic conditions he was working under when we spoke.

"I had all kinds of strange ideas floating around back then. The design department at school was using PCs to print images a lot, and seeing a vinyl cutting machine there gave me the germ of what would eventually become the painting machine," he said. After finishing his undergraduate degree, Xie wanted to see more of the art world beyond China and persuaded his parents to let him study in Edinburgh.

It was only once he got to Britain that he realized how novel the idea of machine-made painting still was, even in countries with much longer histories of contemporary art. He brought the vinyl cutter with him to Edinburgh and made the collaboration between machine and artist the subject of his graduate work.

"For my graduate show in Edinburgh, I exhibited the process itself — the steps I went through using the cutter — and people found it pretty novel," Xie said. At that point he hadn't yet modified the machine; he simply used its two built-in functions, cutting shapes and pencil drawing, as they were.

"What mattered, I realized, was the angle you looked at the cutter from — you could just as easily see it as a painting machine." Back in China, he pushed that collaboration between artist and machine even further.

The machine gives him a level of precision he couldn't achieve by hand, and it's also his way of asking whether a machine could ever really replace a human painter. His relationship to it, it turns out, runs deeper than it might seem. "Getting a machine to actually work takes a lot of trial and error — it's never solved in a single day. I'm refining it constantly, every day. My tool is, in a sense, also a work in itself. It has a double identity," he said.

At Beijing Commune, his newest series, "Vertical Lines," looks from a distance like an evenly graduated field of colored stripes. Move closer, though, and the transitions between the lines turn out to be anything but simple: the surface ripples up and down, and the gaps between the color bands trace a precise, repeating trapezoid.

"There's a clear difference between the tool I used for 'Vertical Lines' and the ones I used before. In the past, the blades on the machine were continuous, tightly packed rows of teeth that dragged the pigment across the canvas. This time, I cut a notch out of the middle of each tooth, which left a gap — and that gap is what traces out the trapezoid," is how Xie described the rippling shapes in the paintings. The show also includes a series called "Dunhuang."

The inspiration is exactly what the name suggests. As a mural-painting student at CAFA, Xie traveled to Dunhuang to sketch, and the murals in the caves there — particularly those from the Western Wei, High Tang and Northern Wei periods — left a deep impression on him: the color, and the sheer skill with which the ancient painters handled it and organized their compositions.

"The repeating, interlocking colors in my work now are the result of absorbing that influence from Dunhuang," he said. The pieces in this series are comparatively small, the colors packed close together — blue against red, yellow against black — in sharp, high-contrast pairings, as if strands of different-colored yarn had been woven tightly together. The small scale, Xie told us, wasn't arbitrary; it followed from the structure, texture and color relationships of the image itself.

"Vertical Lines," in fact, grew directly out of an attempt to scale "Dunhuang" up. Xie found that the tightly woven color scheme simply didn't hold together on a larger canvas, viewed from a distance.

"I tried a bigger version with the Dunhuang color scheme, but the colors were so densely interlaced, the contrasts so sharp, that the composition just couldn't support the scale," he said. So he gave up the sharp blue-against-red contrast and stretched the color range out wide instead, letting the hues shift gradually into one another — as if he'd taken that tightly knitted sweater and pulled it loose in every direction, softening the colors so the sweater could grow bigger. The exhibition also features "Color Stripes," a series he has kept returning to since 2013.

Back in 2012, Xie discovered that acrylic medium held up better than raw acrylic paint — it behaved something like a transparent glue, and it solved the cracking that acrylic paint tends to develop in Beijing's cold, dry winters. That's what started "Color Stripes." "The early 'Color Stripes' pieces used acrylic medium," he told us. "They came out glossy, semi-transparent — it looked especially good against a white canvas." Unlike the "Suspended Blade" works, the "Color Stripes" pieces are made with a blade that does touch the canvas.

As the blade passes across the surface, it leaves a thin white line between each color band. Those white gaps do the work of balancing the color and steadying the rhythm of the piece, the way rests between notes matter as much as the notes themselves in music. The new "Color Stripes" works on view use oil paint rather than acrylic medium — the colors come out saturated, almost fierce, trading the earlier transparency for something more intense.

Asked about his daily life, Xie laughed and said he was, in fact, a very simple person — something close to an office worker with a fixed schedule.

"I get to the studio around nine or ten in the morning and head home around seven in the evening. For me, keeping the creativity going means constantly practicing, waiting, thinking, and sometimes just letting my mind go blank in the studio. Emptying your head out is actually an important part of the work." "And of course, staying physically fit matters a lot too," he added, half joking. "Standing for hours mixing paint, working the machine — it takes real physical stamina.

It's not as if I can just switch the machine on and sit there tapping my foot while it finishes the work. A lot of the time it feels like I'm wrestling with it." He likes to hike and jog in his free time. "Ultimately that's also about staying healthy enough to keep working. What I want is to use the machine's regularity, and the particular character of pigment, to bring people a sense of beauty, order and even the sublime that usually goes unnoticed in the world around us — something that goes beyond visual pleasure alone."

Editor: Huang Xirui. Copy editor: Deng Kaili. Images courtesy of the artist Xie Molin and Beijing Commune.