But once kids outgrow their toys, parents are expected to follow suit.
“Growing up, I saw adults didn’t color. It wasn’t socially correct,” Sandoval said. “Then a few years ago, I heard a radio show about college students coloring with regular coloring books and crayons, and I thought, ‘Oh, that’s cool.’”
Last year, just after Thanksgiving, she saw dozens of adult coloring books at a craft store and bought one for herself along with a set of colored pencils.
Sandoval uses Prismacolor pencils -- a little pricey at $1 to $2 each -- but she likes their wide range of colors, soft finish and ability to blend better than markers. The coloring books can run from $6 to $15, but many have heavy pages suitable for framing.
And her artwork, elaborately detailed pictures, like the colorful head of a lion, could easily be hung on the wall.
For Sandoval, who has an art background, coloring allows her to flex her artistic muscles without having to invest in a lot of expensive supplies. It also fits into her schedule.
“The nice thing is I can work on a little part of it, put it down to give the kids a bath, then pick it back up again,” she said. “I get the same type of reward doing something creative with my hands, but without a whole big process.”
Sandoval knows she isn’t alone in her love of coloring. Just a week after she purchased her first adult coloring book at the craft store, she noticed the number of books left on the racks had dwindled.
“I think a lot of people want to reconnect to something visceral,” Sandoval said. “The amazing thing is it took one person to say, ‘Let’s try this,’ and then a publisher put out the money and marketed it.”
The person many believe is most responsible for starting the craze is Scottish illustrator Johanna Basford, whose 2013 adult coloring book, “Secret Garden: An Inky Treasure Hunt and Colouring Book” has sold more than 2 million copies worldwide, according to Barnes and Noble.
The popularity of coloring shows no signs of diminishing. Five of the top 10 best-sellers on Amazon.com are adult coloring books.
A clerk at Book World in Janesville said besides the wide range of coloring books for sale, there’s also a magazine devoted to the art. There are coloring clubs. An app called Pigment even allows users to color hundreds of designs with an Apple Pencil right on their iPhones and iPads.
The books are tailored to almost every interest. Users can color pictures of Art Nouveau designs, intricate mandalas, Harry Potter characters, worldwide cities, animals or trucks and cars. They can illustrate pages of the Psalms or indulge in more adult-only themes like four-letter words and scantily clad women.
Anita O’Brien, director of Aram Public Library in Delavan, noticed a lot of media coverage on the activity, including articles in Publishers Weekly.
Inspired by the press, she said she gave a family member an adult coloring book as a gift last Christmas. She also offered a coloring class earlier this month at the library and will repeat the class in February. Other area libraries, including Beloit, Delavan and East Troy, have held or are running coloring workshops.
For the last three months, Matheson Memorial Library in Elkhorn has offered adult coloring from 3 p.m. to 4 p.m. Thursdays in the Mary Bray Room. Chad Robinson, adult services librarian, said the library might extend the time this spring.
Robinson said the library provides participants with sheets of pictures, pre-sharpened colored pencils and background music -- from New Age to classical.
While the activity is open to all adults, Robinson said coloring draws predominantly females ages 30 to 70, with a teenager or two showing up occasionally.
The weekly event is called “Zendoodling,” and like the Japanese form of Buddhism that emphasizes meditation, there’s something about the simple act of coloring that’s relaxing.
Jeannie Engerson, a middle school psychologist in the Delavan-Darien School District, said research shows coloring brings the heart rate down and reduces stress.
“Kids having a hard time tend to put negative thoughts and feelings on the back burner when they color,” Engerson said, adding that she’s never had to persuade even middle school students to pick up the colored pencils.
Engerson herself likes to color and said she’s drawn to animal pictures.
“I tend to do it before I go to bed,” she said. “It’s like reading a book to help you relax and get tired.”
Krista Huerta, an occupational therapist with DDSD, has used coloring to help kids develop fine motor skills, improve hand strength and attention spans and lower anxiety.
“The act of coloring affects the amygdala of the brain, which controls fears, and actually makes you more relaxed,” Huerta said.
In a former job, Huerta also used coloring with adults as part of post-stroke therapy, with dementia patients and others.
“I’ve used it for adults who underwent hip or knee replacements, to keep their minds off of the pain, or to ease their depression over staying in bed for extended periods,” she said.
Huerta said coloring often brought back memories to adults of a favorite coloring book or the enjoyment they experienced as children.
She said she likes coloring with her young son.
“I can sit and color a bit of my page and wait for him to finish up his,” she said. “It lets us just stop and focus on what we’re doing.”
Many say coloring on pre-printed pages isn’t as intimidating as creating an original drawing. You simply choose the colors you want. There really are no constraints in coloring, no wrong choices.
Even Sandoval, who thinks about composition and focal point before she colors, said she’s seen pictures using color combinations she wouldn’t have tried, but the results turned out fine.
“My daughter colored a picture of a wolf and she picked some bright green colors I would never have picked, but she was really proud of it,” she said. “She didn’t even stay inside the lines.”