Despite a tough retail environment, graphic novel sales were up slightly in the first half of 2011, it was reported yesterday at the ICv2 Comics, Media and Digital Conference. Although down from their peak in 2007, graphic novel sales were up 3% so far this year. In contrast, periodical comics sales were down 8%; combined periodical and graphic novel sales were down 2%.

The figures were revealed as part of the annual Whitepaper presented by industry analyst and ICv2 president Milton Griepp. Held in conjunction with the San Diego Comic-Con, the ICv2 conference kicked off this year’s edition of the world’s biggest pop culture festival with a look at the business side.

There were some bright spots. The kids graphic novel category is growing quickly. And digital comics sales have doubled since 2010. While precise figures are hard to come by Griepp estimates overall digital comics sales at somewhere between $6 and $18 million.

Elsewhere, Greipp noted, manga sales continued to decline although they seem to have levelled off a bit. He estimates the overall sales of the combined comics sales (periodical comics and graphic novels) in 2010 at $635 million, down from $680 million in 2009. Graphic novel sales declined from $370 million to $340 million in 2010. Graphic Novel sales were down 6% in comics shops, but rose 7% in general bookstores.

In accounting for the decline, Griepp pointed to the general economic malaise, and the well known problems in the bookstore market including the closure of Borders. In addition periodical sales have suffered from content problems, including reader fatigue with big crossover events, and ownership changes at both Marvel and DC, the leading publishers in the comics periodical category.

The rest of the ICv2 Comics, Media and Digital Conference featured panels looking at the state of the market for turning comics into Hollywood films (featuring agents Scott Agostoni, ICM co-head of media rights Nick Harris and Circle of Confusion producer Rick Jacobs); the rise of Transmedia properties and new opportunities to sell digital comics to new readers (moderated by PW Comics World’s Heidi MacDonald and featuring IDW CEO Ted Adams, Dark Horse CEO Mike Richardson and Viz sr. v-p Alvin Lu); and Comics, Paper and Digital (moderated by PW Comics World’s Calvin Reid with Diamond Distributors v-p Bill Schanes, Comixology CEO David Steinberger, DC v-p, sales Bob Wayne and writer and publisher Mark Waid).

Once again this year’s San Diego Comic-con International kicked off with preview night, opening the exhibition floor to fans for three hours from 6-9pm. The place was packed as usual and publishers like Fantagraphics, Top Shelf and Drawn and Quarterly reported that sales and crowds looked good. Dark Horse announced plans to launch graphic novels created by director Guillermo Del Toro and Chuck Hogan (The Strain) with art by Mike Huddleston; YA romance and fantasy author PC Cast (House of Night) with art by Joelle Jones; and from rock musician and Rage Against the Machine bandmember Tom Morello (The Orchid) with art by Scott Hepburn.