What is Coroplast made of?

Coroplast is corrugated polypropylene, a twin-wall plastic sheet with hollow fluted channels running through the center. Picture the plastic version of corrugated cardboard, but built to survive outdoors.

• Lightweight thanks to the hollow-flute construction
• Waterproof, so rain and humidity do not warp it
• Resistant to most chemicals and to UV exposure
• Rigid enough to stand on stakes or H-frames yet easy to cut and handle

Those traits are why it is the default material for yard signs, event signage, and short-term outdoor displays.