From the desk of Bob Boese


Bob Boese - Nov 04, 2013

A group of LSU engineering students were given the assignment to measure the height of a flagpole manually, without algebra. They got ladders and tape measures and went to the flagpole. They fell off ladders, climbed on each other's shoulders and fell again, dropped their tape measures and so on, and eventually the process turned into a disaster.

After a while, a pretty blonde Tulane coed happened by and saw what the engineers were attempting to do. She walked over, asked the custodial crew to pull the flagpole out of the ground, and lay it flat on the ground. She measured it from end to end, gave the measurement to one of the engineers and then walked away without saying a word.

After the coed was out of sight, one engineer turned to another and laughed as he shook his head. "Now that's just like a blonde! We're looking for the height and she gives us the length!"

Many fly fishermen consider measuring their leader/tippet critically important. Formulas are everywhere to be found, from complicated line tapering for long trout leader/tippet to simple straight line for bass. Tippets are a curious product and when sold as tippet are expensive. The least costly tippet monofilament (Cabela's Climax) is approximately 10¢/yd. while the most expensive non-tippet monofilament fishing line (Spiderwire Mono) is approximately 2¢ per yard. Which raises the question, is it worth the difference?

Well, the tippet is special, isn't it? If special means strange, yes, it is. For the fly fishing purist, tippet must be purchased by "X" size. Unfortunately, tippet resides in an alternate universe where 2+2 sometimes equals 5. [This equation is probably attributable to ancients who joined a rope with 2 knots to a rope with 2 knots and ended with 5 knots...think about it....] Nevertheless, for the modern fly fisherman, determining the best tippet size by the traditional "X" rating is frustrating at best.

The Chinese have bred silk worms for five thousand years and if not for the Emperor's fascination with these tiny creatures the history of fly fishing would have been very different. (Silk worms apparently do not appear in nature and are solely dependent on human breeding for their continued existence.) In early days of fly fishing, lines and tippets used by British fly fishermen were silk for line (silk worm cocoon) and gut for tippet (silk worm substance taken from the body of the worm before he spins his cocoon). There was a process for drawing gut through a gauge with holes of decreasing size to obtain a final diameter for a gut leader. One draw was 1X or .010 inches. Three draws resulted in a 3X rating or .008. Metrics didn't count, even though they are shown on practically all monofilament line spools. Why? Because metrics were not adopted by the Brits until the 1960s. Why? Because the French wanted them to use metrics. Even after the 60s, although the UK agreed to use the metric system, the imperial system is still in common and widespread use for tippets.

Why was gauge measurement necessary? Because chalk stream trout were skittish and line shy, tiny flies were mandatory, and with consistent tippet diameter measurement, the fly fisher knew what size tippet he could get past shy trout and through the eye of a tiny fly. For reasons actually known only to the creators of the initial tippet gauge, the process is governed by the rule of eleven. Huh? Exactly. The X rating added to the line diameter (forget decimals) equals eleven. A 5X tippet is .006" and 7X tippet is .004" etc. An 8X tippet should always be 0.003", while a 2X tippet should always be 0.009" regardless of brand. Of course, tippet material might have different breaking strengths depending on the manufacturer's production methods and the elasticity of the monofilament used.

Because sometimes fishing is sort of like Moneyball (choosing a baseball team by certain critical statistics), there is another equation that gives a guideline for the size of tippet to use with certain size flies. The equation is: divide the fly size by four, and then add one. Example: If you are using a size 12 hook, 12 divided by 4 plus one equals size 4X. Size 5X tippet suits a size 16 hook (16/4+1=5). If the result after dividing by 4 leaves a fraction (18/4 = 4 with 2 left over) add one (resulting in 5.5) and know you can use 5X or 6X. Hook eyes are usually large enough that they can accommodate either size. Which means that if you will be fishing 16s and 18s you can know that bringing only 4x to 6x tippet to the water should meet all your needs, which sort of eliminates the logic of the division rule.

Regardless, what follows is a table of tippet sizes.

SIZE DIA (in) Lbs Dia. (mm) if you happen to be French





































You may notice there is a significant range in strength of tippets. Unfortunately, modern tippet manufacturers also come from the 2+2 = 5 school and even with today's precision instruments, uniformity is the exception – tensile strength of tippet differs between manufacturers by several hundred percent. Manufacturing variances also allow the stated monofilament diameter to be off by more than .002 inch. So, how and why does this effect line strength? Because not all tippet is identical, even in the same batch from the same manufacturer.

A monofilament line has a stretch of between 15% and 35% which produces the following inconsistency.

Pound test







diameter (mm)*







*Data was obtained from labeling on various monofilament line packaging.

Monofilament fishing lines are made from liquefied nylon in an extruder which is pressed through fine holes under high pressure. They are cooled in a bath and expanded until they are stretched to the target diameter. These lines are intended to have controlled stretch with a smooth surface but every monofilament is different (and even different batches of supposedly identical mono of the same brand can vary). Essentially, there is no way to predict what precise pound strength you will get from tippet. Knowing generally the strength is probably good enough, but the fact that there is no precision is why monofilament tippets are strange.

In contrast, fluorocarbon is a slightly different process with denser line that is heavier, which makes these lines sink faster. Fluorocarbon does not absorb water, which means the breaking strain and elasticity are not altered by use in the water. It is less flexible, resistant to abrasion and its fame is near invisibility in the water due to its 1.4 refractive index (the degree to which light refracts as it passes through the line). That's closer to the refractive index of water (1.3) than the 1.5 refractive index of standard monofilament. Consequently, a larger stronger fluorocarbon should be able to be used without affecting visibility. But...fluorocarbon line is a much costlier than regular mono – $10/250 yards. Of course, that's versus $10/30 yards for fluorocarbon tippet.

Remember that the typical tapered leader recipe requires 3-5 weights of line and lots of knots. Consider that, by using regular monofilament as tippet, you'll save enough money not buying tippet material to afford a couple of good tapered leaders. In warm water, you can just use the least costly "level line" leader with no taper. A typical level line leader for bass has about 6' of heavier mono (15#-20#) then a short (18") tippet of 8#, or may be all entirely the same weight.

If you are still determined to use tippet and wondering what tippet to choose, the rule of eleven is as reliable as you're going to get.

Two men were sitting next to each other at the Big Lake Bar drinking seriously. After a while, one turned to the other.

"Listening to you, I bet you're from Cameron Parish."

The other man answered, "Yes, I am!"

The first man said, "So am I! What part of the Parish are you from?"

"Grand Chenier."

"Pooyie! So am I! What street did you live on?"

"Main Street by the old cemetery."

"Well Dang, so did I! And to what school did you go to?"

"I went to South Cameron of course."

The first man got excited, and said, "Me too! What year did you graduate?"


"Gah-de-don! Can you believe I graduated from South Cameron in 1972."

About this time, Gautreaux walked into the bar, sat down, and ordered a beer. The bartender walked over shaking his head and muttering.

"It's going to be a long night; the Thibeaux twins are drunk again."

Editor's Note
I learned a slightly different rule when determining the proper size of the tippet to use with a specific fly. I learned to multiply the x size by 4, thus 3x times 4 equals 12. So a 3x tippet is the proper one to use with a size 12 fly and one fly size, 10 or 14, on either side. So a 1x tippet would be the one to use on a size 4 fly, a size 2x for a size 8 and so on.

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