1. Go with a light, easy to breath through fabric.
2. Write on it some Latin phrases, such as Imperium est mentiri te (the government is lying to you), Mens imperium Fabrica (mind control device), Tyrannidem incipit parva (tyranny starts small) or Servitutem Trainedr (slavery trainer).
The Latin will make you look smart and force curious people to look it up. It will be more memorable if they have to do a little work.
Trainer,,,
I could use That,,,