Knots for joining two lines

Knots for joining two lines are important to know. They will allow the angler to create advanced rigs and for the fly fisherman they are key elements when making the leader and for attaching the leader to the fly line. Here is a collection of knots for joining two lines.

Blood Knot
Double Blood Knot
Double Four Fold Blood Knot
Surgeon's Knot
Double Uni Knot
Double Grinner Knot
Double Paragun Knot
Double Centauri Knot
Albright Knot
Simple Simon Double
Cove Knot
Water Knot
Improved Blood Knot
Slim Beauty Knot