<http://schema.org/about>
"Cardboard is one of those underrated materials, often with a short and meaningless lifespan that ends when your package is delivered. Unless you are cardboard in the hands of io10design's cardboard fiends"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/sustainable-product-design/milan-furniture-fair-2010-a-room-made-of-cardboardcan-you-tell.html>