This book provides a simplified and practical approach to designing with plastics that funda­ mentally relates to the load, temperature, time, and environment subjected to a product. It will provide the basic behaviors in what to consider when designing plastic products to meet performance and cost requirements. Important aspects are presented such as understanding the advantages of different shapes and how they influence designs. Information is concise, comprehensive, and practical. Review includes designing with plastics based on material and process behaviors. As de­ signing with any materials (plastic, steel, aluminum, wood, etc.) it is important to know their behaviors in order to maximize product performance-to-cost efficiency. Examples of many different designed products are reviewed. They range from toys to medical devices to cars to boats to underwater devices to containers to springs to pipes to buildings to aircraft to space­ craft. The reader's product to be designed can directly or indirectly be related to product design reviews in the book. Important are behaviors associated and interrelated with plastic materials (thermoplastics, thermosets, elastomers, reinforced plastics, etc.) and fabricating processes (extrusion, injec­ tion molding, blow molding, forming, foaming, rotational molding, etc.). They are presented so that the technical or non-technical reader can readily understand the interrelationships.