I've been making survival bracelets out of 550 paracord and they're lots of fun! The bracelets are also a functional piece of jewelry. The single knot bracelets can have up to 8'+ of cord and the double knotted bracelets can have up to 16'+ of the cord. The inner core consists of seven strands of a thinner thread. If you are camping, fishing, hiking and ever need extra cord in an emergency situation, just unknot your bracelet and you'll be set.
I have also made some bracelets with a thinner 100 pound polycord. You will see some photos of those with two rows of knots. They are a little lighter weight than the paracord bracelets.