It’s tough to think of an art form more closely associated with youth culture than graffiti, but thanks to superstar street artists like Bansky, JR, and Mr. Brainwash, spraypainting has gone mainstream. So mainstream, in fact, that Lisbon, Portugal now has a graffiti club exclusively for the over-60 set.

It’s called Lata65, and its members—who have been dubbed the “graffiti grannies”—range in age from 59 to 90. Despite the nickname, there are several male participants, and also plenty of octogenarians. The name is derived from the Portuguese word for “can.”

The Guardian reports that Lata65 was actually started by two thirtysomethings, architect Lara Seixo Rodrigues and street artist Adrião Resende, with the help of 65-year-old retired doctor turned street artist Luísa Cortesão. The group has organized a series of two-day workshops across Portugal over the past three years, and will soon launch sessions in São Paulo, Brazil. The workshops cover everything from the history of street art to the benefits of using a pseudonym to sign your work “so the police don’t find you,” according to Seixo Rodrigues.

The idea blossomed when Rodrigues began organizing an annual street art festival in her hometown of Covilha, and noticed a stronger interest in the medium from older people than from the younger generations.

“Each year we ran the festival I noticed it was the older people, not the younger ones, who were really engaged,” she told the Guardian. “They were our companions at all hours, day and night, asking us questions about how it was done and commenting on what the paintings represented. I realised there was a real interest in street art among this age group.”

Seixo Rodrigues and Resende work with participants to design custom stencils before they head into the evening with face masks on and spray cans in tow. Many make plans to come back in the future, setting their sights on empty walls in the neighborhoods.

“The more I paint, the more I want to paint,” says 66-year-old Olinda Rodrigues. “I didn’t really like street art that much before this; I always thought it was just kids making a mess of the walls. But now I understand the history behind it and the way of thinking and I appreciate the artists more.”

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Anthony Haden-Guest’s Intrepid Lives of the Street Artists, Part I

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