Meanwhile, DC's archrival, Marvel, has also been gunning for female readers, although its strategy differs. Instead of starting a separate line dedicated to the demographic, the company has been hiring writers known for their established female following. In format, these comics are more like traditional superhero periodicals, but the company's strategy also involves repackaging the material in hardcover and graphic novel formats.

Last year, Marvel launched its "Anita Blake, Vampire Hunter" series of comic books, based on the swift-selling novels by Laurell K. Hamilton. The title character in the series tracks criminals through the sometimes-seedy vampire underground of St. Louis. The series has proven popular with women and brought a range of new shoppers into Carol & John's Comic Book Shop in Cleveland, says co-owner John Dudas. "They came out of nowhere," Mr. Dudas says.

Marvel has brought in other writers popular with women before. In 2006, Marvel began publishing a miniseries on the character Storm, a female mutant member of the X-Men that was written by romance novelist Eric Jerome Dickey. Before that, Marvel hired Joss Whedon, the creator of cult television series "Buffy the Vampire Slayer," to write Marvel's "Astonishing X-Men" title, in part because of his track record attracting women readers.

Such moves have been part of a push by Marvel over the last three years to try new strategies to bring readers to Marvel titles, says David Gabriel, senior vice president of sales and circulation at Marvel's publishing unit. "Before that, the thought was, if you do 'She-Hulk,' that will attract girls," he says.

The moves to attract female readers come as the comic-book industry is at its healthiest point in recent memory. In 2006, dollar sales from dominant distributor Diamond Comics to specialty comic shops rose 15 percent — the biggest jump since comic-and-hobby trade publication ICv2 began tracking figures in 2001. Last year, Marvel Entertainment's publishing-segment revenue — which includes sales to booksellers and comic shops — rose 17 percent to $108.5 million. (Time Warner doesn't break out DC's numbers.)

Barnes & Noble's graphic-novel buyer, Jim Killen, says sales of manga books are roughly split between the sexes. But that's a far cry from traditional comic-book audience, dominated by male buyers.

"We want all of our customers to realize this isn't an exclusive club just for college age males," said Cliff Biggers, who owns Dr. No's Comics & Games in Marietta, Ga. "There's material for everyone. That's what we keep stressing."