There are lots of new sign-making products coming out all the time, so there are often options for what type of materials to use to make your sign. The trend is toward durability and there are several substrates we use that are very durable for outdoor uses.
The substrates we use most of the time are:
Aluminum w/ PVC core
For a full description of these materials and their uses, see the page
“Sign Substrates ~ Materials We Use”