Jean-Michel Basquiat, the late neo-expressionist whose tragic life story inspired a 1996 film, used invisible ink to draw secret figures in at least one of his early paintings, Artnet News reported last month. The figures are easily visible under UV light, and more of the artist's work from this period may contain such hidden drawings.

Invisible ink has been around since at least the fourth century BC; it's mentioned in a treatise on secret communications by Aeneas Tacticus. It's familiar to anyone who has ever gotten their hand stamped when they entered a club so they could be readmitted later by holding it under UV light. There are many different types, but substances that glow in response to UV light include lemon juice, body fluids (hence the use of UV light in forensics), sunscreen, and some soaps and laundry detergents.

But invisible ink is rarely used by artists. One notable exception is the Chinese-born British artist Aowen Jin, whose 2015 exhibit at London's Horniman Museum featured a series of hand-drawn invisible-ink illustrations, which can only be seen under UV light, on the walls and floor of the Music Gallery Performance Space. Apparently, Basquiat sometimes used fluorescent materials and signed one 1982 canvas, Orange Sports Figure, in invisible ink. But this is the first known instance of the artist intentionally embedding secret drawings into a painting.

Basquiat is a classic rags-to-riches story, without the fairytale ending. He struggled in school and dropped out at 17 to attend an alternative high school in Manhattan that caters to creative sorts for whom traditional education was difficult. Kicked out by his father, he crashed on friends' couches and sold T-shirts and postcards to make ends meet.

In 1976, he and his best friend, Al Diaz, made a splash spray painting graffiti on buildings in Lower Manhattan as "SAMO." The two fell out, ending the SAMO project, but the recognition Basquiat gained as a result was the start of his stellar rise in the art world. In 1981, he had his first public showing as part of a New York/New Wave exhibit in Long Inland City, which also featured works by Keith Haring, Talking Heads frontman David Byrne, William Burroughs, and Robert Mapplethorpe.

Soon Basquiat was selling a single painting for as much as $25,000, a princely sum to a man who had been homeless just a few years before. He collaborated with Andy Warhol and David Bowie. He dated a then-unknown Madonna. He painted while clad in expensive Armani suits and was featured on the cover of The New York Times Magazine. But he also developed a crippling heroin addiction and died of an overdose in his art studio in 1988 at 27.

“It’s so exciting to see something that’s literally invisible that the artist put there on purpose.”

It's often said the best thing a promising artist can do is to die young, and that was certainly true of Basquiat; the posthumous market for his work boomed. It's the early paintings from 1981-1983—before the drug addiction took hold—that are the most valued by the art world. (One 1982 painting broke records at a 2017 Sotheby's auction, selling for $110.5 million.) That's how art conservator Emily MacDonald-Korth made the unexpected discovery of invisible ink drawings back in December: a client asked for her expert analysis to determine whether his original Basquiat was really completed in 1981.

That process included pigment analysis and viewing the canvas under both infrared and UV light. (Per Artnet News, this is "typically used to spot varnish or other signs a painting has undergone repair.") That's when she saw the markings: two arrows drawn in what seemed to be black-light crayon. They were identical, readily visible arrows drawn on the canvas. Basquiat may have just been doing so as a kind of guide as he worked on the painting, but he did sometimes paint over images and leave them particularly visible. So MacDonald-Korth thinks it's consistent with Basquiat's "use of erasure."

And it should be very easy to check other paintings by the artist for similar secret drawings—like another 1981 canvas, Poison Oasis, which also features arrows. "Anyone who owns a Basquiat should get a long-wave UV flashlight. They're compact little flashlights. You can get one on Amazon," MacDonald-Korth told Artnet News. "It's so exciting to see something that's literally invisible that the artist put there on purpose, completely intentionally."

Those of us too cash-strapped to afford an original Basquiat will just have to follow the hunt from afar.