Yupo is a terrific product... polypropylene (not quite paper, not quite plastic), flexible, glueable (instantly with crazy-glue), takes pencil, watercolour, Pentel pens and pigments (fantastically), is heat resistent and resistes tearing and ripping...

Available in single sheets in several grades, as well as in pads.

http://www.yupo.com/

What can you do with Yupo?
http://yca.yupo.com/wally2005/past/2003_bracelets.html
http://apollo.fa.mtu.edu/~mabeckwi/slideshw.htm
http://www.elseware.to/products/products.htm
http://www.elseware.to/products/products.htm
How to: http://www.wetcanvas.com/Articles2/250/166/
Yupo Awards (Japanese site): http://www.yupo.co.jp/designcompe/dac_jusho.html