[pct-l] Tarp construction

[Nathan Miller]

I'm considering trying a hammock and tarp this season.  I'm also considering making my own tarp.

I found some info. on the net to the effect that I can make a tarp by taking my larger sheet of Tyvek, wrapping a small portion around a marble wherever I want a tie-off, and then putting a slip knot around the marble to form what are essentially fully dynamic grommets.

I have three questions:
-Has anyone else tried this method?
-Where do I get paracord?  Military surplus?
-Where do I get a small piece of black Tyvek?

-Nate the Trail Zombie