Line Weights

On the package of every fly line is a code. The first element is an an indication of how much the line weighs and what weight class it would fall into under the AFTMA Line Weight Standard. Below is a discussion about line weights.

Line Weight is an indication of how much the first 30 feet of the line weighs, in grains, minus any level tip section at the end of the line - usually 6 to 12 inches. This is according to the now defunct American Fly Tackle Manufacturers Association (AFTMA) standard which attempts to simplify choosing the correct line weight for any given fly rod.

 

 

Unfortunately, in recent years this has become complicated by the fly rod manufacturer's trend toward faster (stiffer) and lighter fly rods, and the tendency for a few fly line manufacturers to design some of their lines heavier than the standard to help load these faster rods; for instance producing a 5 weight line weighing 150 grains. These heavier lines are called half weight lines and are usually found in the mid-weight range trout lines. These factors complicate the effort of a novice to understand the weight system while at the same time solving problems with finding the best line for a given rod and caster.

Though the best method is to try the line on the rod first, in most instances you can match the line to the rod by purchasing the line weight indicated on the rod blank. If the rod is rated for a 6 weight then purchase a 6 weight line. A few manufacturers may have a double line weight indication such as 6/7. This indicates that if you are using a double tapered or long belly weight forward line, the manufacturer recommends using a 6 weight line. If using a standard weight forward they recommend using a 7 weight line since it will weigh less when carrying longer amounts of line.

Another factor, and sometimes the most important, in choosing a line weight has to do with your personal casting style and the action of the rod. If you are used to moderate action rods and have a relaxed smooth casting stroke, you may find that the new fast action rod you bought doesn't feel loaded with the indicated line on it. In this case try casting it with a line that is one weight heavier than the line indicated on the rod. There are times when going up even 2 line weights may be called for. Since there are no standards for rating the line weight of a fly rod this doesn't mean that the rod is not truly what is indicated on the blank. It means that due to modern design trends the rod may be too stiff for your casting style.

Conversely, if the rod feels sluggish with the line you chose, you can try a lighter line.