Several haptic devices have been developed in recent years in order to reproduce the sensation of physical contact with virtual objects. Many of these devices are point-based, and some haptic interfaces behave like small surfaces that conform to a virtual shape. None of these allow a full-hand contact with the shape, and they are, in general, too small to render big surfaces. The simulation of tasks, such as the exploration of aesthetic surfaces made by industrial designers in order to check the quality of prototypes, require full-hand contact with the shape on a one-to-one scaled representation of the object. These explorations follow trajectories that can be approximated with planar or geodesic curves. In this paper, we describe the design and implementation of a linear haptic device that is able to render these trajectories. The device is part of a multimodal system including stereoscopic visualization that allows visual representation of the entire surface. Industrial designers use the system for checking the quality of shapes while exploiting their manual and visual skills. The system has been tested by industrial designers and the results are reported in this paper.