A-frames comes in a variety of materials. The most popular is the cost effective Signacade. It is a light weight plastic, and when filled with water, can stand up to moderate winds.
For those very windy areas, or if you are looking for something a little more substantial, we suggest using a sidewalk sign with a water-fill base, or a custom made MDO A-frame. Both options are great, and they have a larger face area than the Signicade.