This is article gives you a method of identifying a fly line by marking the leader end of the line.
You would mark a 9 weight. as follows. That is done by placing one broad band on the line that being equal to five and the four narrow bands each being one. The broad band is on the tippet end of the line.By the use of color, instead of just black for the bands, it becomes possible to identify the type of line.
For a floating line you would use a green marker for a color of forest for floating.
For an intermediate line you would use a blue marker for a color of indigo for intermediate.
A sinking line is identified by marking the line with a number of red narrow bands equal to the sink rate of the line. The mnemonic for sinking is scarlet or red. An example would be 10 red bands for a Teeney 750 grain shooting head with a sink rate of 10 inches per second.
* Page 26 Lefty’s Little Tips from Lefty’s Little Library of Fly Fishing
Odysseus Editions 1991