Dibond Aluminium Composite Panels
Aluminum face and back, thermoplastic core:
http://www.tri-dee.com/Dibond Aluminium Composite Panels.htm
"This is a lightweight but rigid and durable aluminum composite material (ACM) â€"â€" two strong sheets of .012" aluminum bonded to a thermoplastic core. Yet, it fabricates easily. Dibond Material is pre painted with a polyester finish that is available in 2mm, 3mm and 4mm thickness and in 4'x8', 4'x10' and 5'x10' sheet sizes. Choose from colors of white, black,Red, Yellow, Blue, Brushed Silver, Brushed Gold, silver and bronze. Dibond Material is a UL® (Underwriters Laboratories Inc.) recognized component for electrical signage (UL94V-O). This weather-resistant material is ideal for a wide range of signage and exhibit/display applications including these."
Ron Brown resufaced his elevated layout with Dibond not too long ago and featued an article describing it in SitG.
Google: Dibond