Comment Re:3D Printers (Score 4, Informative) 49
Maybe you haven't seen the SLA printer projects that use lasers or DLP such as LemonCurry for curing photopolymers? Feature sizes are often down to 1 micron per layer and only a few microns for X and Y.
Photopolymers are available in a wide range of properties that are tough enough for use as end products and not just product concept look-a-likes. Photopolymers for inkjet have also come a long way and are also used to create rigid and durable end products with features down to 25-50 microns. What you might be used to seeing are the FDM or FFF (fused filament fabrication) RepRap type printers that print with molten plastics with much lower resolution in the order of 0.3mm.