Optics is an excellent complement to undergraduate study in fields such as mechanical, electrical, or biomedical engineering. Applications in those disciplines are also a great motivation for deeper learning in optics. One area in particular where optics and engineering intersect that is worthy of more attention is three-dimensional (3D) printing (3DP). I describe how optics concepts relevant to 3DP enhance the usual introductory discussion as well as how 3DP can be beneficial to the humbly stocked optics lab. The work concludes with some practical examples of capabilities that have been made possible in our instructional labs through 3DP.