The tippet is level mono (or fluorocarbon) tied to our leader as it shortens after a repeated change of flies.
Mono is a code word for a monofilament thread, but its usage now refers exclusively to nylon in fishing circles. Nylon tippet is a great product and offered by many companies in various test sizes stiffness and even colors. The breakdown of nylon lines in nature is ca 500 years. I implore all anglers to clean up all nylon discards and safely deal with it.
We also have tippet material made from fluorocarbon. It is a great product but the breakdown time of it is worrisome, and very long 5000 years. So again, discard it safely.
The tippet material is loaded onto spools, and marked with breaking test 5 pound or 10 pounds, etc. test strain. Then there is something called X, for instance, X, 2X, or 5X stamped on the spool label. This X system is used to indicate the diameter of monofilament lines. This X denotation comes from the past like so much in our sport. Leaders were made from silkworm guts. The segments were then drawn through dies that shaved off a little bit every passage. 3X had been 3 times through etc. The higher the X number the thinner the tippet. The diameter in inches and millimeters are also given. The trouters love the X system so it stays.
Now the standard is set so that 0X is 0.011 inches thick. Subtract the number prefix to X from 0.011 and for 1X we go 0.011-1=0.010 etc. Now the various sizes can be found in the table
Now it stands to reason that we will not tie 8X tippet to a 3/0 hook. Conversely, we should not tie a 04X tippet #28 dry fly. There must be some parity in the sizes from the hook to the tippet to the fly line itself. Here is a rough guide. The tippet on offer is getting stronger, so now we are getting very strong thinner material. Another rule is to take the fly size and divide by three, which gets you the X number.
I have noticed that saltwater anglers do not worry much about the X denotation. The only thing that I pay attention to when saltwater fishing is the test strength and whether it is mono or fluorocarbon.
You can hear in the saltwater world the term “Shock tippet” and “Bite tippet.” It is the same thing. For toothy critters like Spanish Mackerel, I for instance use a bit of wire tippet tied to the fly. The tarpon crowd likes to have a very strong terminal say 1-2´ tippet portion, 50 – 60 -pound test, because of the abrasive mouth of the tarpon.
The leader is attached to the fly line and its tippet section attaches to the fly. Tapered leaders come ready-made in various lengths and diameters.
It can be a good idea to apply a little bit of glue to a knot to secure it. I use a product that cures in UV light.