After attending the RAPID + TCT 2019 Conference, Piper Jaffray analyst Troy Jensen continues to believe the 3D printing industry is experiencing "solid" growth and that the "long-awaited" production opportunity is gaining momentum. The analyst is "hopeful" the momentum continues and that the industry moves beyond jigs/fixtures, molding and modeling applications to "more innovative" use cases like what carbon is doing with helmets and shoes. Aerospace and automotive appear to be the next verticals to more seriously adopt additive manufacturing and the opportunity is significant, Jensen tells investors in a research note. The analyst has Overweight ratings on 3D Systems (DDD), Materialise (MTLS), Stratasys (SSYS) and Voxeljet (VJET), and he feels most optimistic about Stratasys.