Adequate tooth reduction is a prerequisite for function, esthetics, and longevity of fixed restorations. A tooth reduction guide may be useful for establishing the proper angulation of the tooth and maximizing periodontal health and restorative success. This article describes a simple and versatile technique for an accurate evaluation of tooth reduction for fixed restorations by using a color-contrasting positive guide of a silicone occlusal registration material processed inside a vacuum-formed clear thermoplastic matrix.