Roadside Signs

Hey everyone, I want to help support Ron Paul by making signs to attach to telephone poles, and things like that.

I am a student so money is scarce.

Living in Michigan, the weather is always changing, and I am afraid that my cardboard signs will dissolve if the rain/snow/sleet hits them.

Are there any cost-effective alternatives to using cardboard?

I was thinking of getting lacquer , or maybe using lexan?

Any tips would be greatly appreciated!