This video is all about Fly Line Grain Weight and the miss understanding that High Grain Wt. Lines sink quickly. Grains are a unit of measurement, similar to Ounces, or Grams. They relate the Mass of an object, in this case the object is your fly line. Just like in the gear industry, Fly Rods are designed to be loaded with a specific weight line to perform optimally - the weight of the line being measure in Grains. Grains do not impact the sink rate of a fly line, for example. A 200 grain floating line and a 400 grain floating line....both float. Fly lines are coated in a plastic material that adds mass to them in specific areas to create the desired taper, but this coating is less dense than water. So, it doesn't matter how much they put on or how "heavy" the line is, it will still float. To obtain the desired sink rate, Fly line coating are impregnated with a Tungsten Powder to increase the specific gravity of the material, making the line denser than that of water - hence they sink. Fly line Grain Weight relative to Fly Rod Wt. for a 30ft WF condensed head (plus or minus 25 grains depending on casting style and rod taper)

6wt - 200grains

7wt - 250

8wt - 300

9wt - 350

10wt - 400

11wt - 450

12 wt - 500