I needed to make a stencil that was larger (about 14" x 11.25" or 355mm x 286mm) than our 3D printer. And I wanted the stencil to be plastic, not hand cut paper or cardstock. (Once again the NEED of a laser cutter pops up) By dovetailing or puzzle piecing the parts together I could make any size stencil I might need.
With this method I could also change out just part of the stencil. For example, change out a name or date from within a stencil of text without having to reprint all of it.

No

No

.3mm

solid

This was printed 2mm thick out of PLA, with solid layers.
After printing the parts were glued together using hot-melt glue. It could be taped together to make it easier to change out parts if needed. And finally, I glued the whole thing into a cutout in a piece of corrugated cardboard to catch any overspray.

Video of stencil in use:
https://www.youtube.com/watch?v=ZeORRysHXCE