“[T]he seal impressions of the Uruk period are little masterpieces. At that time the stamp-seal of earlier periods was almost entirely superseded by the cylinder-seal. This was a small cylinder of ordinary or semi-precious stone, varying in length from 2.5 to 8 centimetres, as thick as the thumb or as thin as a pencil, and pierced lengthwise throughout, so that it could be worn on a string around the neck. On its surface was engraved a design which, when rolled on clay, could be repeated ad infinitum. These early cylinder-seals were already made with great skill, and the designs—which ranged from friezes of animals or plants to scenes of daily life or mythological subjects—were compsed and arranged with considerable ingenuity.”

—Georges Roux, Ancient Iraq, third edition, 1992.