There were two basic methods of mould decoration used in antiquity, relief and applied (or appliqués).  Relief moulds, commonly used on terra sigillata, were pressed into the wall of a vessel so that the decoration would appear as an imprint.  In the appliqués technique, characteristic of North African red slipped wares, a particular material was applied onto the surface of a vessel using a mould.  Barbotine was another popular method of design, which was frequently used on drinking vessels.  Similar to modern cake decorating, soft clay is channeled or trailed onto the surface of an unfired pot forming patterns and imagery.  Unlike mould techniques, the quality of a barbotine design depended directly upon the skill of the decorator; although, their purpose - cosmetic enhancement for marketing purposes - was the same.