The aim of this article is to determine whether the process of memorizing a tactile map key, or legend, can be improved by including three-dimensional (3D) symbols produced by means of 3D Printing. The method used in this study involved asking a group of 20 volunteers with different profiles to memorize eight tactile symbols from two keys, each of which had different characteristics: Key 2 included 3D tactile symbols and Key 1 had only two-dimensional (2D) tactile symbols. Results show statistically significant differences between the two keys. Use of Key 2 yielded a 48.72% reduction in the number of errors compared to Key 1 (N = 20, p-value = .014). These data show that combining 3D with flat relief symbols (2D) improves the process of memorizing a tactile key because the 3D attributes can be distinguished from the 2D features by touch. For practitioners, this article provides data about the possibilities of 3D Printing applied to tactile maps, keys, and symbols.