What You Need to Know About Fly Line Leaders and Tippets

A leader is the length of nylon monofilament (nowadays fluorocarbon monofilament is also used) to join the fly line with the fly. A tippet is the final 3 feet or so of leader to which the actual fly is attached.

You can buy tapered leaders which means the thickness of the leader reduces as the the length gets closer to the fly. The leader is tapered for 2 reasons: (1) to assist in tying the nylon to the thick fly line and (2) to help with casting the fly to get an improved presentation. Alternatively you can tie your own leaders by using lengths of differently sized monofilaments and knotting them together. One school of thought says that these self made leaders perform better than tapered knotless leaders.

Leader and Tippet Sizes and Diameters

Nylon monofilament used for tying flies (or hooks in general) is normally given two specifications with regard to thickness (diameter) of the monofilament... an X number and a diameter in mm or thousands of an inch. There is a relationship between the X number and the diameter in thousands of an inch which is worth remembering. To give you an example a 4X monofilament has a diameter = .007 inches. A .009 inch diameter monofilament = 2X.

 The formula is 11-nX=d where d is diameter in thousandths of an inch and n is the X factor.

11-d=nX can be used to translate from a known diameter to an X value. This is important since many references only give an X value.

The higher the X value the thinner is the monofilament. In general the finest monofilament you can buy is 7X or .004inches. This sized tippet would be used fishing very small flies to "fussy" trout in difficult waters and conditions.

Fly selections to choose from.