I found Cornelis Drebbel the way you find the best characters: in a footnote in someone else’s story.

He turns up in Amy Butler Greenfield’s A Perfect Red, which I’m reading this month, as the man behind the brilliant scarlet that made cochineal even more valuable than it already was. But the dye was only one piece of him. Drebbel was an inventor, an engraver, a chemist, a maker of improbable machines, and, apparently, a man spectacularly bad at converting genius into money.

There is a portrait of Sultan Mehmed II in the National Gallery in London that has been nagging at me for years.

The first time I saw it, I was not thinking about diplomacy, trade, or the fall of Constantinople. I was looking at the painting itself.

The arch around the figure did not feel like ordinary Renaissance architecture to me. It felt like the edge of a manuscript page. The decorated cloth, the jewels, the gold, the contained darkness behind the Sultan, all of it seemed closer to ornament, calligraphy, and courtly display than to the kind of Venetian portrait I thought I knew.

Even the profile seemed to have crossed a border.

Something about the painting felt translated. Not wrong. More like a sentence spoken in another accent. The grammar was familiar, but something underneath it had shifted.

I have been reading Amy Butler Greenfield’s A Perfect Red, and it has already sent me off in several directions.

That is usually how I know a book is working on me. It does not stay inside its own covers. It starts attaching itself to other things I am looking at, writing about, or painting. From this one book, I found my way to Rembrandt, to cochineal, to Cornelis Drebbel, to military uniforms, to trade routes, to insects, to empire, to the astonishing fact that a color can carry half the world inside it.

That is the great subject of A Perfect Red: not red as an idea, or red as a symbol, but red as a material fact. A color made from tiny insects. A color people desired, guarded, stole, traded, imitated, taxed, wore, painted with, and fought over.

A color is never just a color.

While reading Amy Butler Greenfield’s A Perfect Red, I came across Titian’s portrait of Charles V on horseback.

The moment I saw it, I thought of Rembrandt’s The Polish Rider.

That surprised me. I do not know Rembrandt’s work particularly well, and I had never seen the two paintings discussed together. But the connection was immediate. Not scholarly. Not proven. Just visual.

There they were: two riders, two horses, two paintings separated by roughly a century, and something in the structure of one seemed to call out to the other.

Did Rembrandt know Titian’s painting?

After writing about Gentile Bellini’s portrait of Sultan Mehmed II, I found myself asking a different question.

Not who commissioned the painting.

Not why Bellini was sent to Constantinople.

Not even whether he had been looking at Persian and Ottoman miniatures.

I wanted to know how the picture was made.

Jim Elledge’s biography Henry Darger, Throwaway Boy places Darger in the realities of his time and place. Darger was born in Chicago in 1892. His mother died when he was very young and his sister was put up for adoption. Darger was placed in Catholic schools and later in institutions for boys labeled “feeble-minded.” Conditions in those institutions could be harsh, routine, and authoritarian. There was little accountability and almost no space for a child to name his own experience, or to be believed when he did.

After my opening at the Soprafina Gallery in Boston several years ago, friends invited me to dinner with an oncologist* and his wife. Over the meal, he told me about his research. He had access to mountains of data collected from patients over many years, and he and his team were struggling to mine it for patterns that might predict cancer. This was before artificial intelligence could handle such a task. He had resorted to color-coding the data. I told him he was heading for trouble.

It wasn’t until I stood in front of Diego Velázquez’s Las Meninas that I understood that I, as the viewer, was the subject.

I had seen the painting countless times in reproduction. I knew the arguments, the diagrams, the mirror at the back of the room reflecting the king and queen. Intellectually, it all made sense. But none of that prepared me for the quiet, almost disorienting recognition that occurs when you are actually there, standing where the king and queen stood.

I was watching a short Instagram video by @evie_hatch, an art historian and pigment specialist, about a material I had never really considered before: Vivianite.

She was showing this strange, unassuming substance—something that can begin almost colorless, even gray—and then, with exposure, with time, it turns blue. Not a bright, declarative blue. Something quieter. A blue that seems to come into being rather than arrive fully formed.

I once traveled to California with a friend, where we stayed with some friends of hers. They had a Rembrandt portrait hanging in their hallway—or so they said. When they asked me what I thought of their Rembrandt, I blurted out, “That’s not a Rembrandt.”

I once attended a dinner at Jan and Warren Adelson’s home. Their New York gallery is known for its collection of American Impressionists and the work of John Singer Sargent. As I moved through the house during this charity event for the Hudson River Museum, I began to recognize paintings at a glance—Sargent and Eakins, a drawing by Ingres, a grisaille gouache by Homer, a medallion by Saint-Gaudens. Nothing was labeled. It was a home, not a museum. But the work announced itself.

Then, over a desk, there was a painting that stopped me. At first, it looked like scratches of color. After a moment, a waterfall began to resolve, but what held me was the color—a very particular Veronese green. And then it clicked: Twachtman. John Henry Twachtman. Adelson confirmed it.

I’ve always been struck by how specific an artist’s palette can be. Not just a preference for color, but something closer to identity.

When Surrounded Islands appeared in Biscayne Bay in 1983—eleven islands ringed with floating pink fabric—the work felt unmistakably whole. Monumental, precise, improbable. It looked like a single idea carried out with absolute conviction. What it did not appear to be was a late addition to an already established practice. And yet, in a quiet but consequential way, it marked a public shift: the acknowledgment that Christo and Jeanne-Claude had always been working together.

With Bernd and Hilla Becher, collaboration is not expressive. It is procedural. The work announces itself through repetition, restraint, and refusal. Two people, one method, sustained over a lifetime.

Their photographs of industrial structures are often described as neutral, even deadpan. Water towers, blast furnaces, gas tanks. Shot straight on. Overcast light. No drama. But neutrality here is a discipline, not an absence. What the Bechers built together was a way of seeing that required agreement at every level. Subject, angle, distance, timing, sequencing. Nothing could drift.

Sonia and Robert Delaunay are usually described as collaborators through theory. Simultanéité. Color as vibration. Perception over subject. All of that is true. But for me, the collaboration only really comes into focus when you put their paintings next to each other.

Two of the most searching artist biographies of the last half century, Van Gogh: A Life and Jackson Pollock: An American Saga, were written by the same partnership: Steven Naifeh and Gregory White Smith.

What makes their collaboration notable is not simply the scale of research, though that is formidable, but the way two voices combine without blurring. Naifeh and Smith worked closely for decades, reading, arguing, corroborating, and revising together. The books emerge from a shared process of verification and interpretation, where assertion is continually tested against evidence.

With Anni and Josef Albers, collaboration does not announce itself through shared objects or joint signatures. It appears instead through parallel concentration. Two practices, rigorously separate in material, moving toward the same questions with extraordinary discipline.

Gilbert and George present perhaps the most literal form of collaboration in this series. They did not align two practices or share a method. They declared themselves a single artist, split across two bodies, and then lived that declaration without exception.

The first time I read Roger Fry, my immediate thought was: finally, someone who looks at a painting the way I do. Not emotionally first, not narratively, not in search of reassurance or uplift, but through a disciplined form of attention. What we now call formalism felt, in his writing, less like a theory than a discipline—a way of agreeing to stay with what is actually there. Fry’s focus on line, color, rhythm, and spatial structure was not a narrowing of meaning but a refusal to dilute it.