styrofoam covered with fabric wall art. My daughter and I did this for her room. We used cheap painter canvas and scrapbook paper. We sprayed adhesive glue to the canvas and layed the scrapbook paper on top.
How to Make a Cardboard Box Marble Labyrinth Game - Frugal Fun For Boys Engineering STEM activity for kids - Build a cardboard box marble labyrinth! Get the marble through the course without it dropping into the holes.