Page 51 - Geoffrey Budworth, Jason Dalton "The Little Book of Incredibly Useful Knots"

Double grinner knot

You can join two lines of similar size, weight, or strength together with two identical knots

which, back-to-back, slide together. Each of these versatile knots is more widely known,
however, as a uni (universal) knot, because, its fans claim, it can also be made into a loop or a
snell to hook and lure.

Bring together the two lines to be joined, parallel, with the working ends pointing in opposite

directions. Create a loop with one end (1), then tuck four wrapping turns through it (2) and tighten
(3). Turn the work end-for-end and repeat the process (4, 5). Pull on the standing part of both
lines to unite the twin knots (6).