Blow molding has emerged as a commercially viable process for manufacturing parts for nonpackaging/industrial markets. This article discusses the machinery required, processing methods, mold types, process parameters, part designs and material distribution of blow molding. It provides an outline of the parison programming system equipped with blow molders to control the parison thickness. The article describes factors that are usually considered to minimize material distribution problems, namely, design, material selection, process control, part performance, and cost.