In a joint project, a study was launched between our two groups to provide a reliable die design for an EPDM profile used in a pneumatic flexible mobile system patented by Conti-Tech. While the geometry of the profile does not appear at first sight to be overly complex, the presence of details of small dimensions and the tolerances required complicate the task of the designers. Concurrent experimental and numerical trials were thus conducted to provide a die which performed the task, while also satisfying additional requirements: reproducibility, limited disturbance to the flow pattern, short times to reach production conditions. Several approaches are tried to meet those criteria, from the application of the automatic die design capability of the software, to the numerical trial of modified dies, and finally to the evaluation and testing of a completely original die design.