We compared the production processes of ready-to-wear for high-end in Italy and Japan. We specifically took into account the works of modelists from these countries to understand how their differences influenced the resulting characteristics of garments. By designing and producing a tailored jacket for women in Japan and Italy, we explain features of different working styles in these countries. We report details of each production stage in particular by predicting the jacket silhouette from body patterns and investigating the characteristics of sleeve patterns. We also investigated the specification sheet for keeping tape and interlining. We found that the concept for producing a jacket differed depending on the country, even for patterns. The predicted silhouette of bodies made in Japan was more planar shapes and linear lines in sleeve, shoulder and waist. On the other hand, the predicted silhouette of bodies made in Italy was loose fitting and three-dimensional. We also showed that interlinings and keeping tapes were used to make more three-dimensional-appearing bodies in Italy. This depended on the discretion of the modelist in Italy.