A very safe knot for joining two lines of similar thickness. It is best to leave the running ends relatively long for additional safety. The Flemish Bend doesn’t slip along the rope. It might be difficult to untie, but it is not susceptible to jamming, nor does it damage the rope.
Put the 1st running end under the standing part to form a loop.
Pass over the standing part.
Thread through the loop from beneath to form the 2nd loop of Figure-8.
Pass the 2nd running end under the central part of Figure-8.
Pass over the 1st standing part, following the 1st loop.
Continue following the 1st loop and pass under the 1st standing part and over the 1st running end.
Now follow the 2nd loop and pass under both left ends.
Finally, pass through the 2 right loops, following the 1st standing part.
Tighten the knot.
The Flemish Bend is complete.