NEW YORK (CBSNewYork) — Adult coloring books have now become so popular that the New York Public Library now holds workshops in more than 19 branches.

WCBS 880’s Marla Diamond visited one branch on the East Side of Manhattan, where devotees talked about why they love it so much.

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Beth Cooper said she gets lost within the lines, and for the subject of her coloring, “I chose flowers because it’s been a little gloomy.”

It was Cooper’s first visit to the Kips Bay Library’s adult coloring book club, started by senior librarian Elisa Isling.

“You don’t have to have any prior skills, but you can really create something that you’re proud of,” Isling said.

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Wendy Sirache, a retired teacher, is a regular at the club.

“You’re so focused that you’re not thinking about your ailments. And it is kind of Zen-type relaxation because… it’s getting away from the computer and my devices,” she said.

Adult coloring has become so popular that one of the books by illustrator Johanna Basford made the New York Times Best Sellers List last year, CBS2 reported back in July. Now, mainstream publishers are getting in on the action.

Experts said the act of coloring engages both sides of the brain, relieving pressure and stress.

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Coloring is often used by art therapists to help both children and adults to communicate more effectively.