Trilene knot is used to tie to terminal tackle like lures, hooks, swivels, snaps, etc. It is really no harder to tie than an improved clinch knot, but it is much stronger than an improved clinch knot.
The reason is that the Trilene knot is one in which the line makes two trips around whatever it’s being tied to (hook eye, swivel eye, etc.). There are several knots that use this method, and there is proof that knots tied this way are stronger than knots in which the line only passes around the eye once.
The Trilene knot can be used with braided lines, monofilament, or fluorocarbon. We have used this knot in situations ranging from fishing for stocked trout in lakes to fishing for halibut.
To tie the Trilene knot, pass the tag end of the line through the eye of whatever you’re tying to twice. Do not pull these wraps tight yet. Wrap the tag end around the standing portion of the line four times (for mono or fluorocarbon; six times for braid), then thread the tag end through the loop formed just above the eye. Moisten the knot, then pull both the tag end and the standing portion to cinch the knot down. The tag end should be protruding from the knot 90 degrees to the standing line. If it isn’t, the knot is probably not cinched down all the way. Trim the tag end once the knot is correctly and fully seated.
With this knot, it is critical that the two wraps of line going around the eye do not cross. If they do, knot strength will be compromised. If the wraps cross, cut it off and try again.
The Trilene knot cinches down tight to the eye of whatever you’re tying it to, so if you’re looking to maximize the action of a fly or lure, this is not the best knot to use. In that case, use the non-slip loop knot.