A fishing leader and tippet are what separate the fly from the fly line and provide an “invisible” transition from the line to the fly. A leader is made of monofilament or fluorocarbon, with fluorocarbon being the more expensive of the two. Nowadays, most fly fisherman use tapered leaders, which start with a thick butt end and taper to a specified diameter toward the other end.
fishing leaders come in a variety of lengths and weights. The most common leader lengths for trout are 7.5 foot and 9 foot leaders, but can be longer depending on the type of water being fished and how spooky the fish are. The strength of a leader is measured in a pound test (e.g. 4.75 lb) or an “X” rating (e.g. 5X). As the “X” increases, the pound test decreases. For most trout fishing, it seems the recommended leader strengths are 4X-6X, but clearer water or spookier fish may warrant a 7X or even smaller.
Tippet material is tied to the end of the leader to extend the length of the leader and provide a length of monofilament that can be clipped back as you change flies without chewing up your tapered leader. This is typically the same diameter or smaller than the end of the leader and for beginners should not be longer than 24” or so. New tippet can be tied onto the leader and it is shortened, thus extending the life of a leader.