Taken from Wikipedia:
Coleman is best known for intricately detailed portraits of subjects both famous and infamous: artists, outlaws, serial killers, movies stars, friends, and family. He paints with a single-hair brush and uses a jewelers loupe; much of the detail is not visible to the naked eye. The majority of his portraits portray the central subject in the center of the canvas, lozenges containing biographical scenes and details from the subject's life ring the central image. Humorous imagery is often placed beside scenes of tragic family incidents.
His work draws as much from Coleman's beginnings as a comic book artist as from historical precedents. His paintings are most often compared to those of Hieronymus Bosch, and his work has been exhibited alongside canvases by the Dutch master