If a child did it in a restaurant, his mom would slap him on the wrist, but Jason Baalman was playing with his food on a recent episode of "Late Show with David Letterman."
Baalman has gone from a struggling portrait artist in Old Colorado City, Colo., to a YouTube sensation in just the last few months.
His Internet fame landed him on the late-night talk show, where he painted a picture of stage manager Biff Henderson in ketchup, using french fries for paintbrushes.
It's a goof on a comedy show, but Baalman says he did his best to create a quality picture.
"I didn't want to be the person that was doing something stupid for attention," Baalman said.
"Of course it is silly. I mean, why would you paint with ketchup and french fries? It is absurd, but I didn't want it to be only something absurd."
The whole experience still feels odd to Baalman, a 30-year-old who started posting videos on YouTube, an Internet video site, as a way of promoting his portrait work. He recorded himself painting Morgan Spurlock, creator of the fast-food documentary "Super Size Me" and Ronald McDonald, using ketchup and fries.
With that, his YouTube views went from a couple hundred a week to millions.
"It was just something that would attract a little more attention than just a pencil or a charcoal," Baalman said. "I was just trying to use it as a marketing tool that potential clients could watch. It became its own thing."
A video of Baalman painting with chocolate syrup and a spoon was also a hit, but his real smash was a video showing him drawing the Mona Lisa using the Paint utility that's been a standard accessory in Microsoft Windows for decades.
"Paint is something that everyone's familiar with," he said of the project, which he did in about two hours, timelapsed into a four-minute video. "Everyone's tried to use Paint and failed."
He's also done a series of portraits of famous YouTube users, including an upcoming project of an Australian You-Tuber done with Vegemite on toast.
As successful as all of this has been -- Baalman now has a huge backlog of portrait orders -- he's aware he could be typecast as the guy who paints with food.
"It entertains me and it entertains other people," he said, "(but) sometimes I feel that it has pigeonholed me."
In New York, people kept asking him how long he's done ketchup art.
"And I was like, this is the third one I've done," Baalman said. "To me, it's just a different medium, but I don't want to be known as the ketchup artist."
Baalman has no formal art training; he grew up in Houston and studied biomedical engineering at the University of Southern California, then worked in Internet marketing in Los Angeles.
He moved to Colorado Springs in 2001 to help his parents, who own the Rocky Mountain Chocolate Factory around the corner from his studio, and became an artist on the side, notably painting and repainting the large mural on the side of the chocolate factory.
Baalman plans to make posters of his original ketchup art and sell them to benefit CARE, the global poverty charity.
He's also thinking about inviting other local artists to post their own videos on his corner of YouTube.
The Letterman show? Baalman said it was stressful balancing painting his portrait while a director talked in his ear, Henderson stole french fries and the cameras turned on and off.
"It was rush, rush, rush ... and sit," he said. "It was very difficult to do the painting."
Still, he thinks he did Henderson proud in the end.
"I knew they were trying to make fun of me and that the purpose was to try to make a funny skit," he said. "My whole goal was to do something that would be impressive to people."