When designing CG characters, “the two things you want to stay away from are pure white and pure black,” says surfacing supervisor Sabrina Riegel.But on “How to Train Your Dragon,” the first thing co-director Chris Sanders told Riegel’s team was that he wanted the toon’s lead reptile, Toothless, to look like a black panther, cutting a sleek silhouette from a distance but rich in detail when seen up close. So unlike the rest of the pic’s bright, colorful dragon menagerie, that posed a considerable challenge. “How can we make him look like he’s not wearing a rubber Batman suit?” Riegel recalls. “You can’t go to the zoo and look at a dragon for reference.” Riegel, who holds a degree in sculpture, has been “painting” characters at DreamWorks Animation (and before that, PDI) for almost 15 years. Hands-on work with fiberglass, ceramic and metal kindled her interest in surfaces, which has in turn impacted everything from green-skinned Shrek to “Madagascar’s” furry zoo crew. To achieve the desired effect, the surfacing artists, who determine colors and textures for everything onscreen, blended aspects of multiple creatures, from snake- and sharkskin to stingray and crocodile hide, giving the sandpapery scales a subtle sheen. They collaborated closely with the lighting department, placing light sources to reveal the texture and adjusting levels to bring out the character’s form. Riegel refers to that step as “sculpting” with light. Though her crew supplied the texture, without an assist from lighting, all Toothless’ ebony micro-detail would have been lost.