Back in spring semester of my freshman year, I was in a class called "Intro to Fibers". We learned all kinds of things, including felting.
This was a product of an experiment in felting yarn in between thin layers of white wool. I laid out black yarn in the shape of a labyrinth, felted over it, and later embroidered on top. The inner yarn is more visible when held to the light.
I surrounded the black yarn with backstitching, and julienne stitched across the top. I'd like to eventually finish this, perhaps as a light fixture (in some non-fire-hazard set up) or as a window hanging.