My daughter is autistic and needed a way to visualize the word "Stop" and The word "Go".   I made this sign in multiple sizes for use everywhere.  I cleaned up the smaller one to take up the least amount of material but also stay stiff and usable.

This was designed in Tinker Cad:

https://www.tinkercad.com/things/ag8h6B69u2i-stop-go-sign