Sheet Bend

Best for joining ropes of different diameters.

Intermediate

Use cases

Joining ropes of unequal size
Extending a rope
Net making and temporary repairs

Steps

Form a bight in the thicker or stiffer rope.
Pass the thinner rope up through the bight from behind.
Wrap the thinner rope around the back of the bight.
Tuck the working end under itself (above the bight) and tighten.

Try another knot

Square Knot Bowline Clove Hitch