Emily Macdonald-Korth, an art conservator in New York, thought she was going in for a routine forensic job last month when a client asked her to confirm that the Jean-Michel Basquiat painting he owned was in fact done in 1981, as he’d been told.

She planned to conduct pigment and elemental analyses, take technical photographs, and look at the picture under UV and infrared lights. It was all checking out normally until she brought out her handheld UV flashlight, typically used to spot varnish or other signs that a painting has undergone repair, and turned off the overhead lights.

That’s when she saw them: drawings that Basquiat had made in invisible ink.

“I start looking at this thing and I see these arrows,” Macdonald-Korth told artnet News. She flipped the lights back on to make sure she wasn’t imagining things and the arrows disappeared. She flipped the lights off again and there they were: two arrows drawn in what looked like black-light crayon, virtually identical to other arrows drawn visibly on the canvas with red and black oil sticks. “I’ve never seen anything like it,” she said. “He basically did a totally secret part of this painting.”

In fact, this isn’t the first time Basquiat has been known to use fluorescent UV materials. In 2012, Sotheby’s London discovered that his painting Orange Sports Figure from 1982—done just months after the one Macdonald-Korth analyzed—contained an invisible-ink signature of the artist’s name in the bottom right corner. But he has never been known to include UV-specific imagery in his work.

It’s not clear whether Basquiat intended the invisible drawings to serve as an underlying guide for the painting, or if he considered them an element of the completed work. But Macdonald-Korth thinks they fit into his larger process of painting over an image and leaving it partially visible, “so there’s a history there, having something secret there,” she said. “He must have been playing with a UV flashlight and thought, ‘this is cool.’ It really relates to his use of erasure.”

Macdonald-Korth suspects that more UV drawings will appear on other canvases if owners take the time to look. For instance, one of Basquiat’s most famous works, Poison Oasis, is also from 1981 and contains arrows. “The location of one of the arrows I found is in almost the same place as on Poison Oasis, but pointing down rather than up,” she said. “I bet we’d find these on Poison Oasis.”

And it wouldn’t be hard to find out. “Anyone who owns a Basquiat should get a long-wave UV flashlight. They’re compact little flashlights. You can get one Amazon,” she said. “It’s so exciting to see something that’s literally invisible that the artist put there on purpose, completely intentionally.”

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