Even then, his folksy demeanor garnered significant attention. In 1993, he was featured in promos for MTV. His technique, called “wet-on-wet,” allowed him to finish painting a scene in about 30 minutes. Mr. Ross said in a 1990 interview that he was not paid to do the show. Instead he made millions selling how-to books and painting videotapes, and licensing his name for paints, brushes and easels.

He acknowledged, too, that his honeyed voice caused some viewers to nod off. “They watch it strictly for entertainment value or for relaxation,” Mr. Ross told The Orlando Sentinel. “We’ve gotten letters from people who say they sleep better when the show is on.”

Michael Acton Smith, a founder of Calm, said in an interview last week that he was browsing in a bookstore in San Francisco’s Noe Valley more than a year ago when he came across Mr. Ross’s “Happy Little Accidents: The Wit and Wisdom of Bob Ross,” chock-full of the artist’s iconic idioms. Mr. Ross spoke fondly, in particular, of the landscapes he painted with “happy little trees.”

“I thought he was quite mindful,” Mr. Acton Smith said.

Mr. Acton Smith grew up in Marlow, about 35 miles from London, and had not heard of Mr. Ross. So he looked him up online and came across his show. “His voice blew me away,” he said. Back at the office, the Calm staff gushed about the artist. Then Mr. Acton Smith found out Mr. Ross was dead.