The textured oriented overgrowth (epitaxy) of certain metals evaporated on to substrates consisting of highly oriented ultra-thin thermoplastic polymer films has been known for a few years. However, the origin of the observed epitaxy was not clear : the formation of a chemical interface layer, classic epitaxy or graphoepitaxy (artificial epitaxy) all seemed to be possible explanations for the observed orientations. We have used the complementary methods of transmission electron microscopy (TEM) and scanning force microscopy (SFM) to investigate aspects of the polymer-metal epitaxy. Our investigations show that the bulk morphologies of polymer substrates determine their surface topographic properties. Highly oriented surface steps serve as suitable locations for an oriented growth of the evaporated metals. The results of the investigations suggest artificial epitaxy (graphoepitaxy) as an effective orientation mechanism for the oriented metallic growth on polymer substrates.