Patternmaking and moldmaking are the first stages in a casting process whether the materials involved are either metals or plastics. The development of a pattern is a crucial part of the overall molding process. Results from an investigation to automate the process of patternmaking will be presented. This investigation focussed on three major areas; development of a rule-set for parting, parting search strategies, and back draft detection. While no “official” set of parting rules exists today, a collection of rules was developed using various sources of casting literature and in plant pattern surveys. Using this rule set, a parting procedure was developed which was realized through the use of computers and solid modeling technology. Results from these procedures have proven successful enough to warrant continued research in automated pattern design.