There are several webpages here that discuss how to use Tyvek.

Tyvek is a man-made sheet product, lighter and stronger than paper. It can be painted, stamped, embossed and stitched. Then heat will distress the product, changing the appearance entirely.

How to use Tyvek: http://www.joggles.com/tyvek.htm

The Threadstudio's hints for Tyvek and Expandaprint (note you will need to cut and paste this entire link):

http://www.thethreadstudio.com/hints/what's_new4.htm