Cul de Canard, or CDC, as it is commonly referred to, is a finely-fibered duck feather with unique floating capabilities. French for “Duck Bottom”, CDC is buoyant due to its natural oils and does not require additional floatants. CDC is often used for tying emergers and dry fly patterns. It can be stacked and tied in as a wing; tied in by the tips and palmered, used as a soft hackle feather; spun into dubbing loops or used as a dubbing material.
Note: When using floatants on patterns utilizing CDC, be sure not to apply it to the CDC plume, as this will counteract its natural buoyancy