The clove hitch with a quick release has been around a long time,
but the butterfly method of tying this knot is - to my knowledge - my invention.
Once you gain proficiency with this knot, tying it should take about 3 seconds. It is that quick and easy. Scroll down this page while counting slowly 1...2...3, and you will get the basic idea.
Hold a length of cord in front of you, directly in line with the photo. Hold the cord in exactly the same way that I am. This may seem simple, but I have seen dozens of ways of doing it wrong. Don't repeat any of them.
Note: The line leading to the left is attached to the tarp. The line leading right is the short, free end.
Twist the cord in your right hand by rolling your thumb toward you. This forms a loop.
Again, there are many ways of doing this incorrectly.
Note that the cord coming from the right hand goes over the cord from the left hand.
Grasp the base of the loop between finger and thumb of the left hand, then slide the right finger and thumb to the right.
Roll the right thumb toward you to create a second loop.
Place the right loop under the left loop.
Grasp the base of both loops between left finger and thumb. Then slide the right finger and thumb down and to the right.
Extend the left pinky and place it under the line.
Wrap the line under the finger and bring it up.
By the way, the two loops are the "wings" of the butterfly.
Lay the cord between the wings.
Grasp the cord between finger and thumb, along with the others. Now you can let go with the right hand.
Insert the stake between the two loops.
Note that nothing about the left hand has changed from the photo above.
Withdraw the left pinky, and insert the right one.
Pull the left line to tighten the knot around the stake, while still supporting the quick release loop with the right pinky.
Finished. The line in the left hand leads to the tarp. The other line (you can see its free end) is what you pull to instantly untie the knot.
