Check out
this article detailing the seven most likely mistakes some make when designing and and installing outdoor signage. To summarize:
- Don't forget to make it UV resistant.
- Make sure it's easy to read from a distance.
- Make sure it's waterproof.
- The substrate needs to be able to withstand extreme heat and cold.
- If the signage is in a graffiti-prone area, it pays to have it laminated or coated in some way.
- Plan for professional installation if need be.
- Don't let big shipping bills wreck your project, plan ahead.