Anyone who rides a motorcycle lives, to some degree, in the margins of society. Where members of the herd drive Toyota Camrys and hipster hatchbacks, bikers opt for Harley-Davidsons, Triumphs, and Ducatis, putting themselves out there with raised middle fingers thrust at the ordinary citizens of the world. Just as a motorcyclist's ride is an affront to the sensibilities of the meek and the conventional, so too is the ink on their skin. Tattoos have...