in what’s the most comprehensive description of what makes these feathers so unique, Hans’ Tying with CDC article is a must read for any fly tier.
“The description “Cul de Canard” was reputedly coined in the late 1950s by French tier Henry Bresson for one of his patterns. The description has contributed to some confusion, especially when it was literally translated into English as “duck’s butt” or “duck’s arse” feathers.
CDC’s history in fly tying and fly fishing begins in central Western Europe in the 1920s and the dry flies used by fishermen living in the Swiss Jura Mountains near the French border. These patterns, generally referred to as Moustique (Mosquito) patterns, remained unchanged until well into the late 1970s.”
(just to set things straight, the feather’s official name is Croupion de Canard or ‘duck’s rump’. Bresson’s somewhat clever-quirky sense of humour later turned the name of his famous fly into Cul de Canard or, ‘duck’s ass’: cul being a rather vulgar term (at least in those times) for those lovely globes we cherish so much)
historical and frenchytude niceties aside, the Understanding CDC chapter is where we get to the nitty gritty with such goodies as the four feather types, why applying floatant to them renders them useless, harvesting, tips and tricks and how to select the right feather for its intended use.
fly shops all-too-easily sell us any old sort of cdc feather even if they’re all from the preen gland they vary greatly in stem size (flexibility and strength), fibre position and length. safe to say this explains why so many anglers sometimes have difficulties getting the results that seemed so simple at first.
While the natural oils on the feather assist in repelling water, the hydrophobic properties and the structure of the CDC feather are fundamental to its floatability.
Feathers are completely made up of the protein keratin. They are built to be as light as possible in order to make the bird fly easily, yet are extremely strong and waterproof at the same time. Keratin in many ways resembles manmade plastic. One aspect is that it does not soak up moisture, or indeed oil. The oil can only coat the feather parts, not become an internal part of it.”
click either image to access the complete article on GFF. included at the bottom of the page is a step-by-step and video tutorial of Hans’ notorious CDC and Elk. enjoy !