In reply to Oliver Smaje:
> I don't think double fishermans is safe on webbing. Correct me if I'm wrong.
I am not sure why you think this. If you look on the DMM website, at the topic on Knotting Dyneema, the strength of the Water/Tape Knot, Double Fishermans and Triple Fishermans, all tied in Dyneema tape, are compared; the Double Fishermans is stronger (safer?) than the Water/Tape Knot. I have no reason to believe this result would not be reproduced in the 1" nylon tape that was in the original question on this thread
In tape the Tape Knot is less bulky and looks neater than a Double Fishermans Knot but it does have the alarming disadvantage of tending to loosen and so become unsafe.