JAd.
Normand is correct on the differance.
I make furled leaders using 6/0 Uni tying thread. 2 & 4 lb. flourocarbon and .005 Nylon clear quilting thread.
A properly made "Furled" leader can be "Cast" by it's self. Thus you may turn over 4 - 5' tippits.
The break strength of a furled leader is approx. 3 times the material used strength.
May I suggest Kathy Scott's DVD available from Gate's Au Sable Lodge (a sponsor) to get you off on the right track.
P.S. The cost of the furling board is less that 2 purchased leaders!!