 Hughes sometimes uses colored markers to embellish parts of a convention sketch, as when he uses red for female characters' lips, or a silver pen to render scenes set in outer space.When rendering an entire sketch in grey tones or full color, Hughes, who once used Prismacolor or Design 2 markers, explained at the 2010 San Diego Comic-Con International that for the past four years, he had been using Copic markers, a set of which a fan gave him as a gift, because Copic markers are refillable, and because he found that they produce longer-lasting colors, and can be used several times longer than other brands, as he was still using the same package of nibs as of August 2010 that came with the first set of Copics he was given four years previously.When using Copics, he takes care to erase his pencils, and to not work dark-to-light, because of the mottled effects that result from doing so.