The top-selling graphic novel on the 2017 NPD BookScan chart was not the latest volume of the Walking Dead or a classic like Batman: The Killing Joke. It was a kids’ book: Dog Man Unleashed, the second book in Dav Pilkey’s Dog Man series.

The second and third bestsellers were also Dog Man titles—more than one million copies altogether—followed by a parade of Raina Telgemeier books (Drama, Ghosts, Sisters, Smile, and her Baby-Sitters Club adaptations), as well as Shannon Hale’s Real Friends, Svetlana Chmakova’s Awkward, Cece Bell’s El Deafo, and Victoria Jamieson’s Roller Girl. According to BookScan, all these books sold more copies than the first adult title on the chart, Marjane Satrapi’s Persepolis.

Graphic novels for middle grade readers are the hottest category in books right now, but the category was almost nonexistent 15 years ago. In the 1940s and ’50s, comics were a mass medium, with millions of copies sold at newsstands and on magazine racks. Research published in 2014 by Carol Tilley, an assistant professor at University of Illinois at Urbana-Champaign, found that 95% of elementary school children and 90% of teenagers read comics.

The industry hit a downturn in the mid-1950s, when Frederic Wertham (a psychiatrist and author of the notorious 1954 anti-comics work, Seduction of the Innocent) and other social critics waged a widely publicized campaign against comics, claiming they led children to violence, crime, and sexual deviance. To avoid outside censorship, the Comics Magazine Association of America adopted the Comics Code, which prohibited any depiction of sex, violence, and even disrespect for authority figures. From 1954 on, wholesalers would only accept comics that bore the Comics Code Seal of Approval (with a few exceptions such as Classics Illustrated and Dell Comics).

Specialty comics shops began to appear in the early 1970s, and their business model allowed publishers to bypass wholesalers and therefore the Comics Code. These shops also purchased comics on a nonreturnable basis, meaning publishers could tailor print runs to orders. As comics moved from newsstands to specialty shops, the audience grew older and more adult, and publishers catered to those readers with darker, more complex story lines.

The manga boom of the late 1990s and early 2000s created a new format and a new audience for comics. Published as 200-page graphic novels and distributed mainly in bookstores (particularly Waldenbooks, which were mostly located in malls, and the now defunct Borders chain), manga was accessible to young readers (and girls in particular) in the same way that monthly comics had been to earlier generations.

“Without manga, I think bookstores might still have been less open to the possibilities of selling graphic novels, and comics might have remained something more geared toward an adult readership,” says JuYoun Lee, deputy publisher and editor-in-chief of Yen Press, who launched the middle grade imprint JY under Yen Press last year. JY’s books include Svetlana Chmakova’s original graphic novels, Awkward and Brave, and she is republishing the W.I.T.C.H. series, a graphic novel series produced in the mid-2000s by Disney.

According to Lee, “Not only has manga shown that comics is a medium—not a genre—capable of telling any kind of story, but it’s also cultivated a new generation of creators who understand the medium well and are ready to tell their own stories.”

The growing success of manga during those years caught the eye of Terry Nantier, whose NBM Publishing was a pioneer in marketing graphic novels through bookstores, beginning in the late 1970s. Nantier cofounded Papercutz, a children’s graphic novel publishing house, with Jim Salicrup in 2005. It launched with Nancy Drew and Hardy Boys graphic novels, both done in a manga visual style.

“It was a merger of the two styles of comics, with the page size and thicker books and stylized art coming from manga, but the storytelling approach and color coming from American-style comics,” Salicrup says. Papercutz later switched to other graphic novel formats, and their current line is a mix of licensed titles, including the Smurfs and Nickelodeon’s The Loud House, imported titles from France (Ariol, Dance Class), and original graphic novels. In 2017, Papercutz launched the Charmz imprint, which specializes in graphic novels for preteen and early teenage girls.

Also in 2005, Scholastic v-p and creative director David Saylor launched Graphix, the graphic novel imprint of Scholastic. Saylor says he fell in love with comics when he was in elementary school, so that was the age group he focused on. “It also felt like our first acquisition, Jeff Smith’s Bone series, fell in there perfectly—a creative-driven story for grade school kids that also can go older,” he says. (In fact, Bone was originally self-published by Smith as single-issue comics and trade paperbacks aimed at a general audience.) Graphix has gone on to become the most successful publisher of children’s graphic novels, home to a lineup of bestselling creators, among them Kazu Kibuishi (Amulet), Dav Pilkey, and Raina Telgemeier.

From the beginning, Saylor had an eye on Scholastic’s book clubs and book fairs, which market a wide range of titles, including graphic novels, to elementary grade readers. “When the clubs and fairs are on board with a book, it really helps—just the number of impressions we are getting from kids and teachers and parents,” he says. Indeed, in February 2007, when the children’s graphic novel market was still relatively small, Ed Masessa, the category manager for fantasy, graphic novels, and science fiction for Scholastic Book Fairs, estimated he’d sold four million graphic novels since 2004.

Publishers took note. First Second, a graphic novel imprint under Macmillan’s Roaring Brook Press, was founded in 2006; its line includes Jorge Aguirre and Rafael Rosado’s Giants Beware!, Shannon Hale’s Real Friends, and Ben Hatke’s Zita the Spacegirl and Mighty Jack series. Pioneering comics editor Françoise Mouly launched the independent Toon Books in 2008 as a publisher of hardcover comics for early readers, and she added a middle grade imprint, Toon Graphics, in 2014. The comics publisher Boom! Studios launched its kids’ imprint in 2007, starting with licensed comics and later branching out into original comics and graphic novels. It currently publishes the middle grade series the Backstagers, Goldie Vance, and Lumberjanes under its Boom! Box imprint.

Jeff Kinney’s Diary of a Wimpy Kid, a runaway bestseller in 2007, helped pave the way for the category at Abrams Books’ Amulet imprint, which publishes a mix of prose and graphic novels. While not strictly a graphic novel, Wimpy Kid is more visually oriented than most chapter books and is often included in graphic novel sales charts. Other Amulet titles include the Nathan Hale’s Hazardous Tales series and the multiple-award-winning El Deafo, an autobiographical graphic work about living with deafness, created by Cece Bell.

More recent entries into the field are Amp! Comics for Kids, the children’s imprint of Andrews McMeel Syndicate and home of the Big Nate, FoxTrot, and Phoebe and Her Unicorn books, along with Lion Forge Comics, a startup that publishes middle grade graphic novels under its CubHouse imprint.

Raina Telgemeier’s Smile, an autobiographical work about childhood dental misadventures, was the first true middle grade graphic novel to become a massive bestseller. It stayed on the New York Times paperback graphic novel chart for 240 weeks and would probably still be there if the Times hadn’t discontinued its graphic novel charts. The success of Smile and her other books—Drama (2012), Sisters (2014), and Ghosts (2016)—helped bring attention to the category. By the mid-2010s, graphic novels were being carried in chain and independent bookstores and mass market stores such as Walmart and Target, making them as accessible to young readers as any other type of book—and once the readers found them, they wanted more.

Library Demand Heats Up

Around the same time publishers were waking up to the potential of children’s graphic novels, libraries were getting on board as well. “I can remember when we didn’t have a graphic novel collection at all,” says Eva Volin, supervising children’s librarian for the Alameda Free Library in Alameda, Calif.

In 2002, the Young Adult Library Services Association held a graphic novel preconference at the American Library Association’s Annual Conference. “That started the ball rolling, at least in the library world,” Volin says. “Once the format was accepted by teen librarians, we started seeing collections forming in children’s departments. There wasn’t much out there, but the few books we had were so popular that I was buying multiple copies just to keep up with demand.”

Abrams Books executive editor Maggie Lehrman, editor of the Nathan Hale books, has seen how the popularity of a graphic novel can grow organically. Abrams is also publisher of the Cece Bell's award winning graphic novel, El Deafo, edited by Susan Van Metre. “What I think has been incredible about [the Nathan Hale] series is that it’s been such a slow but intense build,” Lehrman says. “We launched in 2012 with two titles and modest sales—no chain or mass support, so mostly in the indies and libraries. And then every book has built on that to the point where the series will hit half a million copies sold soon.”

She continues: “I think it’s the teachers and librarians who put the books in kids’ hands and then the word of mouth from kid to kid. Plus, Nate has had an impressive school visit schedule—he sees hundreds of kids in person and gets them excited about drawing and history.”

Lehrman touches on two important points: the gatekeepers who bring the books to the readers, and the authors who work hard to build a brand. Just as newsstands and magazine racks brought comics to the general public in years gone by, book fairs, book clubs, teachers, and libraries bring graphic novels to potential readers right in their schools. (The Scholastic Book Fairs alone reach 35 million schoolchildren with more than 130,000 book fairs nationwide per year.)

“I run the book fair at my kid’s public school, and they just go straight for the comics at those things,” says Andrea Colvin, v-p and executive editor at Lion Forge. “Anything you put in there that’s a comic is going to sell, and that’s a great place for [kids] to find out about them. And we can’t get enough of them. Raina’s books still sell like crazy.” And as Colvin explains, there’s a secondary effect that may be even more important: “I think kids’ main avenue of discovery is other kids, because kids are encouraged to read and bring books to school.”

Bringing not just the books but also their creators to schools also helps boost sales. “It helps increase the number of access points where kids see an author’s work,” says Graphix senior editor Cassandra Pelham Fulton. “When they do an event, the school or library often orders books, and many kids are exposed to books for the first time in their schools. It’s really cool to see Raina and Kazu on their book tours, interacting with kids directly and telling the story of their books and how they created them.” She adds that even authors who don’t do national tours but just engage their local library and bookstores can widen their audience.

The increasing recognition of graphic novels by mainstream literary awards programs—starting with the nomination of Gene Luen Yang’s American Born Chinese for a National Book Award in 2006—also gave the medium a boost. The profile of graphic novels has grown steadily since then; in 2015 Cece Bell’s El Deafo was a Newbery Honor Book and This One Summer by Jillian and Mariko Tamaki was a Caldecott Honor Book and won a Printz Award. Noelle Stevenson’s Nimona was a finalist for the 2015 National Book Award, and in 2016, March: Book Three by John Lewis, Andrew Aydin, and Nate Powell became the first graphic novel to win a National Book Award.

In addition, Gene Luen Yang served as the 2016-2017 National Ambassador for Young People’s Literature, which brought wider attention to his work as he toured the country and promoted reading in general—including graphic novels. Though only El Deafo is a middle grade title, all these honors helped open the doors of libraries and classrooms to middle grade graphic novels.

While the audience has grown for graphic novels as a whole, it’s the middle grade books that dominate the category. Somehow graphic novels have turned out to be a natural fit for elementary school readers. “That audience is open to anything, and the books you read at that age really help form your character,” Lee says.

Colvin believes that students in the middle grades are still flexible enough to adapt to reading comics—while older readers who are new to the medium may have a harder time. “[Middle graders] are still young enough to assimilate this way of receiving and working with information, where it’s visual and textual at the same time,” she says. “It’s not the same as a picture book, but you’re coming off picture books, so you know you can read words and pictures and put them together to make something completely different.”

Colvin adds, “Kids are into authentic stories and nonfiction and memoir. There’s something about the way comics work—it’s easier for them to project themselves on these kinds of characters. Kids are so interested in Raina’s teeth. Everyone wants to know what her teeth look like. It’s also because they are able to identify with this experience, and a lot of middle grade comics are cartoony enough that everyone can feel like they are Raina.”

Some comic shops have tapped in to that audience as well. Boston comic shop Comicopia is located in an urban area that doesn’t have a lot of children, but manga manager Morgana Rhalina Hartman (who also handles all-ages titles) says middle grade graphic novels are popular with customers in their late teens and early 20s. “I think part of it is that a lot of stories are being told that readers have been waiting for a long time, like a lot of stories with LGBTQ themes,” she says. “We try to make our store a safe place for people of all identities, so for us to have a large selection of queer material is very important.” Their most popular middle grade titles include Katie O’Neill’s Princess, Princess Ever After and The Tea Dragon Society (both published by Oni Press), along with the Backstagers series by James Tynion IV, with art by Rian Sygh.

The children’s graphic novel market is still new enough that there’s plenty of room for innovation. “When Smile came out, it was unique,” Colvin says. “When Wimpy Kid came out, it was unique. The things that are going to do well are things we haven’t thought of yet. I don’t want something that’s like Smile, but it’s about my ankle instead of my teeth. I don’t want to say there isn’t a market for also-reads, but I also want something that is new and different and has a different take.”

Salicrup offers a similar view. “One of our biggest successes ever was the Lego Ninjago graphic novels,” he says about the popular licensed property. “If we made our decisions on what to publish based solely on what was most successful, we would’ve passed on Ninjago, as it didn’t have that much in common with Raina Telgemeier’s bestselling graphic novels. Yet our Ninjago graphic novels were right at the top of the charts with Raina’s wonderful books for quite a while, and not a single Ninjago guy ever wore braces!”

At the end of the day, kids have always loved comics—it’s just that the comics went away for a while. “I haven’t really seen a surge in the popularity of graphic novels,” Volin says. “What I’ve seen is that there has been a surge in books for people to buy. I’d be willing to put money on graphic novels for kids being wildly popular since the dawn of time, if they’d only been available. Sigh.”

Brigid Alverson writes regularly about comics for PW.