Adult coloring book sales have slowed somewhat since the holiday frenzy of 2015, but the category is still one of the hottest segments in the industry. This has publishers and media companies—including some that have never before published a book—looking to experiment with the form and find more ways to get their titles to stand out in a crowded marketplace.

In some cases, this means producing coloring books paired with other products. Newbourne Media LP, a Canadian company specializing in CDs and digital music content, has launched a new side of its business to capitalize on the coloring trend. The Color with Music series pairs books with CD inserts intended for “stress relief.” Its tagline, “Color your way to calm,” shows the company’s focus.

Harris Sterling, Newbourne’s executive v-p of strategic marketing and business development, said the music part was easy. It was dipping into the publishing world that presented a challenge. “We took our strength, which is music, and commingled it with a category that has been explosive,” Sterling said. “We’re thrilled, and it’s turned our company upside down a bit. Priorities and focus have really shifted.”

Although the category’s name implies a more grown-up take on the activity of coloring, Newbourne has found that part of the appeal is in its agelessness—something that a social media initiative inviting colorers to share their completed pages has proven. “The people who are sharing are definitely not seniors,” Sterling said. “The target market is so broad. It’s like Adele’s records.”

Despite Newbourne’s late entry into the adult coloring book market, Sterling said the launch has gone well. Four Color with Music titles (listed at $12.98 each) out of the 10 currently available were in BookScan’s top-selling nonfiction art category as of April 18, and that’s before distribution has gone national. Combined numbers to date for the four books total 51,357 units sold. The company has also inked a deal with Peek-A-Boo Publishing Group for a new children’s book series called Read, Color & Learn with Music, which will be written by author and Emmy Award–winner Don Hoffman. Currently, Newbourne is selling its products to music accounts and specialty retailers it has worked with in the past. Sterling said that while standalone music accounts are no longer a major sales factor, Newbourne is selling direct to bookstores, along with less traditional outlets including big-box retailers, discount stores, national drug chains, warehouse clubs, and e-tailers. The company has no single distributor, preferring instead to work with a number of major book distributors and wholesalers in the U.S. and Canada.

The numbers are so good that Newbourne is looking into less tested packaging ideas, such as new books with colored pencils included. Most publishers haven’t branched into more complex packages, but since Newbourne has handled music packaging for years, it’s accustomed to the process. The first of this line will be released this month, and preorder numbers are strong.

Another company focusing on the wellness aspect of coloring is HCI Books, the original publisher of the Chicken Soup for the Soul series. HCI is sticking to the standard coloring book model, but with a twist—its new Inkspirations series pairs tranquil scenes waiting to be colored with inspirational quotations from the likes of Mahatma Gandhi and Maya Angelou. Its first two titles were Inkspirations for Recovery, which was released in February, and Inkspirations for Women, published in March.

Kim Weiss, HCI’s director of communications, said that even though the books have been out for a short time, the rollout is feeling as exciting as it did for Chicken Soup—especially in the mass market. “The formula we used for Chicken Soup seems appropriate for these coloring books,” Weiss said. “Sales are robust. We’re doing the lion’s share at Walmart and Target and grocery stores, but everybody’s carrying them.”

HCI, unlike most publishers, prints its own products, and this has enabled them to create a greeting card line, on sale July 5, to complement the coloring books. Each unit includes a package of eight colorless cards, for a list price of $15.95. It’s a fitting combination for a publisher long dedicated to putting out titles in the self-help, health and wellness, and relationships categories.

“Everybody talks about the therapeutic value of coloring,” Weiss said, “and we could actually put our money where our mouth is.”

At Workman, even more experimental concepts are in the works. The publisher found initial success in the adult coloring category with a drop-in wall calendar called Color Your Year. The first 40,000 copies sold to accounts within about a month of printing, and Workman’s publisher and editorial director, Susan Bolotin, said they “easily could have sold 60,000.” While follow-ups are planned in four different iterations—page-a-day, wall, notepad, and engagement—the most innovative new developments involve a series called Paint by Sticker.

“We didn’t approach them as a replacement for coloring books, or even going into the coloring books market,” Bolotin said. “They were born out of the minds of the people in our kids department.” In lieu of more traditional coloring book images, employees in Workman’s children’s department rendered images in “low-poly art,” a computer graphics style in which geometric polygon shapes create a three-dimensional effect. In the eponymous initial book in the Paint by Sticker series, offerings include a chugging steam train and a red fox; its companion volume, Paint by Sticker Kids, includes a dinosaur and a medieval castle. Both were released on April 5.

“The immediate response has been extraordinarily positive,” Bolotin said. Paint by Sticker now has 115,000 copies in print, and Paint by Sticker Kids has 50,000 copies in print. New books in the series are on the slate as well, including Paint by Stickers Masterpiece, which includes polyhedral versions of such classic paintings as Vermeer’s The Girl with the Pearl Earring, and Paint by Stickers Zoo Animals. A combined total of 105,000 copies have been printed for the two titles, which will both be released in September.