Favored by flyrodders for connecting tippets to fly lines, the perfection loop is strong, reliable and can, with a little practice, be tied to produce a very small loop at the end of the line. This knot is also sometimes used to attach lures to monofilament lines, allowing a more natural movement than afforded by clinch or improved clinch knots. It can also be used to construct a monofilament leader or tippet that steps down with several lines of differing thickness.