The non-slip loop knot is a knot that belongs in every fly angler’s bag of tricks as it allows the fly to move through a much greater range of motion than a standard knot, like a Uni or an Improved Clinch.
For most knots, I start with the hook in my left hand and the line in my right but for the non-slip loop, I’m more comfortable with just the opposite, line in the left and hook or fly in the right.
Start by going 6 or 7 inches up your tippet and making a simple overhand knot. Tighten it down a bit but not all the way. Thread the bitter end of the tippet through the hook eye and then pass it through the opening in the overhand knot. Notice how the line goes back through the hole in the exact opposite way it came out. This is important. You don’t want it to come from underneath the hole and out the top. Pull on the tag end to close down the loop that goes through the hook eye. Don’t fully tighten the overhand knot but make it smaller and bring it down reasonably close to the hook. At this point, this is how the knot should appear. You may recognize it as a simple slip knot.
Now, pinch the knot between the thumb and index finger of your right hand. Then get hold of the tag end with your left and begin making wraps around the running line. I don’t think it matters in which direction you make these wraps, clockwise or counterclockwise. But it does matter how many you make. I’m only going to do 2 wraps here because of the thick fly line. I usually do 4 or 5 turns with heavier mono and fluorocarbon and 6 or 7 with lighter stuff. When you’ve completed the wraps, once again, pass the end of the tippet back through the hole in the overhand knot. Notice how all three passes enter and exit through the same side of the hole.
To tighten and seat the knot, pull in opposite directions on both the running line and the tag. This will compress the knot but still leave an ample loop to the hook eye. You can then cut the tag end off leaving a short nubbin for insurance.
This is what the knot looks like with more reasonable materials. Make an overhand knot 6-7 inches up the tippet. Pass the end through the eye of the fly. Then pass the end down through the hole in the overhand knot, in the opposite direction from which it came. Pull on the tag and the running line to slightly close the overhand knot and bring it closer to the hook eye. When you’re satisfied with its size and position, pinch the knot between the thumb and index finger of your right hand, and with your left, begin wrapping the tag end around the running line. Here I’m using 20 lb test mono so I’m going to make 4 turns. With the turns complete, for the final time, run the end of the tippet through the hole in the overhand knot. Notice, once again, how all three passes enter and exit through the same side of the hole. Pull in opposite directions on the tag and the running line to seat the knot and create a loop that won’t slip. This can take some doing, especially with heavier line. Finally, reach in and snip the excess tippet off close. I like small loops because they allow a wide range of motion but are still close enough to the hook eye that they don’t look out of place.
Here are a couple of tips that really help with this knot. Prior to completely seating the knot, lubricate it with saliva. There are a lot of things rubbing together here and lubrication really helps. Even with the knot well-lubed, using forceps or pliers to get hold of the tag end makes closing the knot properly a whole lot easier and, once again, do leave just a little bit of tippet protruding from the knot for insurance.
A non-slip loop knot can be used whenever you want a fly to have more action in the water. I, for one, can’t imagine fishing a Clouser Minnow without it. The same holds true for almost all streamers. I’ll also use it on nymphs, particularly bead heads, to give the fly more jig-like movement. I’ve heard that people use them with green weenies to increase the motion of their paddle-like tail. I wouldn’t know as I never have to resort to using such patterns and have no idea how a couple dozen of them ended up in my fly box.
The non-slip loop knot isn’t especially easy to tie or get seated correctly. Even with a good bit of practice it can be a little time consuming. But, it’s absolutely worth the extra effort. As I said in the beginning, it’s a knot that every fly fisherman actually every fisherman, should know how to tie.