The presented research deals with the development of comfortable male underwear taking into account the development of pattern block methods and the analysis of the relationships existing between the compression pressure, the knitted materials properties, and some push-up effects. The main aim of this study is to achieve the technical selection of the materials based on KES-FB evaluations.The ease value has been used as the main index to connect the structural design of underwear, on one hand, and the body sizes, on other hand. A “bodyshell” system for testing the soft tissue of male bodies by FlexiForce sensor has been implemented. The pressures under the shells at six different places on the male body with ease changing have been tested.The collected results including maximum-possible pressure and material tensile indexes measured thanks to KES-FB have been analyzed in order to find the most relevant indexes of the material properties. A mathematical equations based on relationships combining theoretical model with practical application have been established. These equations will be helpful for the consumers and designers to select “the suitable knitting materials for male underwear” and they can be used too in the perspective of parameterization in CAD, in order to improve product developments efficiency.