brhokla:
The finishing knot I believe you are referring to is a whip finish. You CAN do it without a tool which is easy; or if you prefer, with one of the many tools available. I prefer a tool since I've been doing it that way since I started tying.
There is an EXCELLENT article by Dick Talleur in the current issue (Autumn 2005) of Fly Tyer Magazine that covers all of the whip finishing tools and how to use them plus how to whip finish without a tool. Try and get yourself a copy.
[This message has been edited by Bamboozle (edited 12 September 2005).]