What should i use for my project?

ok so we have to make a project for english about a book and the theme and so the theme im representing is the dangers of closed mindedness and we have to have a symbol, motif, etc... for the project and we just have to represent those things visually, so what i was thinking was that i would get/make a box and on the inside put the thoughts of closed minded people and on the outside put the thoughts of open minded people and add other stuff, blah blah blah... so my question is what should i use for the box? should i just use a cardboard box? should i make one out of something? should i buy some sort of box? i really dont know what to do...any suggestions would be extremely helpful!