This paper presents an application of Augmented Reality (AR) in Rapid Prototyping (RP) of non-textured rigid curved surfaces. By enhancing the prototypes with AR, evaluation of its design and aesthetic concepts in real-time becomes easier, saving time and production costs. In our application, no fiducial markers are required and the CAD model used to build the prototype is applied in an edge-based tracking system specially designed to deal with curved shapes. Results from a pilot user study comparing the use of a 3D software and the proposed application are also presented. © 2012 IEEE.