In this session we explain how to become confident in the virtual garment simulation. The process is based on a parallel session for creating a real garment on a real person alive, and then to simulate the same garment on her 3D avatar using Modaris 3D Fit, Lectra virtual prototyping solution. A person has been scanned using a body scanner, and then introduced into the virtual world to process a virtual try-on on her own body. The parallel development of the garment on the real body and on her avatar enhances how to judge the fitting of the garment. Results show how defects in garment construction can be detected as part of a virtual prototyping process, compared to the physical samples and relating to the clothing skill. The user then becomes confident into the virtual try on as a professional tool A symmetric process then takes place. The user develops a style, using Modaris, the 2D lectra software, simulates the try-on in the virtual environment of Madaris 3DFit before deciding to cut and assemble the physical garment and finally try it on.Benefits to the development of prototypes can be evaluated.As a result this session claims to belong to an industrial virtual prototyping.