3D body scanning and printing are attracting attention as innovative technologies for producing dress forms. While designing dress forms, the shape of the human body must be accurately reflected in the different postures. This study explored the development of dress forms as a tool to understand changes in body size and shape according to postures and reflect this information to design and fit evaluation in the apparel industry. The holistic development process of dress forms in standing and sitting postures was suggested for representing the body shape of a specific target group. The average shape of middle-aged Korean women was derived by analyzing the 6th Size Korea data. A representative participant whose dimensions were closest to the average size was selected among recruited participants for the dress form development. The body data were acquired with a portable 3D scanner and corresponding dress forms and accessories were modeled using 3D CAD software. The models were inspected and corrected through prototyping. Full-size dress forms in standing and sitting postures were printed using a fused deposition modeling (FDM) 3D printer and post-processed. Completed dress forms were body-scanned and their accuracy was evaluated through morphological similarity comparison, cross-sectional image comparison, surface area and volume comparison, and mesh deviation analysis. Although there were some minor differences caused by the modeling process, the developed dress forms reflected the main characteristics and shapes of the representative body satisfactorily.