Two- and three-dimensional marks made by footwear are not entirely dependent on the transfer of the greater pattern area of the sole. These additional markings, referred to as edge characteristics, are found as linear striations that are made by a particular portion of the shoe or boot's edge. Typically, edge characteristics have been observed most often in 'plastic' substrates such as mud and the only known method of simulating these impressions involved creating an impression using a similar type of substrate such as modeling clay. This article describes some of the difficulties encountered when simulating edge characteristics and explains the need for more research. (Published Abstract) Figures, tables, and references