fly fishing line

Fly line comes in many colors, such as bright yellow, fluorescent green, pumpkin orange, just to name a few. With so many different colors which one should you choose?
For a sinking line, generally, it is best to choose a line in the darker colors, such as brown. Although this point is open for debate. most fly fishermen seem to agree that when sub-surface fishing, fish may see the brighter colors better than the dark colored fly lines.
Fishing a floating line, the color of the line is generally immaterial as far as the fish goes. When a fish is looking up, it is bound to see the line, except at night, when a dark line may be beneficial.
When a fish is looking toward the surface of the water it will see the fly line regardless of color, since the line itself is lit up by the sky light which will cause it to cast a shadow. Although arguments arise quite often on this point. Generally, it is best to choose a color YOU can see. Bright colored fly lines are much easier for the angler to see, especially when fly fishing with nymphs.
This is especially true in low light conditions, when seeing the fly line is nearly impossible, the angler must instead rely on the action of the fly line.
There are many codes on fly fishing line boxes around the world to decipher.
Here are some examples of these codes to help when you are looking at them in the store.
DT-4-F: Double taper fly line, with a weight of 4 and it floats
WF-5-F: Weight forward taper fly line, weight of 5, it floats
WF-10-S: Weight forward taper fly line, weight of 10, and is a sinking line.
         How fast the line sinks (it's sink rate) will be listed on the box.
DT-7-F/S: The fly line is a double taper fly line, a weight of 7, is a sinking - tip fly line. The sink rate of the fly lines, as well as how much of it actually sinks, will be listed on the box.
L-5-I: The fly line is a a level taper fly line, weight of 5 and is an intermediate sinking fly line. The sink rate of the fly line will be listed on the box.
ST-6-F: This fly line is a shooting taper fly line, weight of 6, and it floats.
Fly line weight: The weight of the fly line should be the same as the weight of your fly rod and reel. Using the wrong weight of fly line will unbalance a fly rod, resulting in poor casting and a long day on the water.
Fly line taper: The taper of a fly line refers to the enhancement made to the fly line to provide better casting. The most popular taper is weight forward taper, which is the ideal fly line for beginners. The weight forward taper fly line is also the most versatile line available.
Fly line density: Density of a fly line refers to whether or not the line will sink or not. A floating line should always be used by beginners because of the fly line's versatility as because it is the easiest to cast.
Fly line color: For top water fly fishing, get a fly line that is easy for you to see in all light conditions