It would be an error to venture into the world of emergers without
taking a moment to look at CDC flies. I suspect most fly tyers don’t
understand the importance of CDC flies or maybe they don’t understand
where and when to use CDC flies.
First of all, CDC is an acronym for cul de canard, a type of feather
found near the preen gland on most birds. However, the CDC we are
looking for is found on ducks and geese, especially ducks.
Preen oils collect on these feathers and often saturate them, leading to
the myth that it is the oil that makes CDC float. In fact, it’s the
structure of the feather that makes it float so well. Dyed CDC feathers
often don’t have any of the preen oil left on the feather, it was
stripped during the dying process, but they float as well as the natural
feathers.
Preen oils collect on these feathers and often saturate them, leading to
the myth that it is the oil that makes CDC float. In fact, it’s the
structure of the feather that makes it float so well. Dyed CDC feathers
often don’t have any of the preen oil left on the feather, it was
stripped during the dying process, but they float as well as the natural
feathers.
Originally published c. May 11, 2008 on Fly Anglers Online by Al Campbell.