Peacock typically comes in three forms; swords, which we’ll ignore for now, eyes, which are basically the tips of full feathers, and strung herls, that come from lower down on the feather.
Strung peacock herls are available in a variety of lengths, making some more suitable for certain applications than others. Most of the time strung bundles are naturally colored, but they can also be dyed for a slightly different effect.
Peacock herls can be used to create the full body of a fly or a small part of it, like a thorax collar. You can wrap multiple herls at a time or just a single herl, as on this size 24 midge.
Good quality eye feathers are often hard to find and more expensive but I think they’re really worth it, for reasons we’ll cover in Parts 2 and 3. Herls from the eye can be used as is or stripped, either physically or chemically, to produce bare quills. The bare quills can be left natural, dyed or colored. They’re most commonly used to create beautifully segmented and slender bodies on flies.