Tooth-reduction guides offer a more controlled and conservative tooth preparation. Many types of tooth-reduction guides are available such as those with horizontal or vertical reduction grooves. A transparent cross-shaped tooth-reduction guide allows the clinician to make vertical and horizontal depth grooves to evaluate tooth reduction in all directions. The reference grooves on the guide enable the clinician to use a periodontal probe to measure the reduction accurately, and the transparent material provides a clear view of the entire tooth. Controlled tooth reduction offers a more conservative approach that is key for long-term bonded ceramic restorations. The multiaxial rigid transparent tooth-reduction guide could facilitate the provision of ultrathin handcrafted porcelain veneers to predictably fulfill patients’ esthetic demands while preserving more tooth structure. The use of technically sound and artistically documented photographic evidence further underscores the effectiveness of this approach, particularly when intra-enamel preparations and adhesive luting under rubber dam isolation are employed. The present article describes a novel 3D-printed guide design that allows the clinician to perform the reduction grooves and evaluate the preparation in the horizontal and vertical directions within the same guide.