There are basically two types of CDC feathers available to fly tiers today – standard CDC, which is just labeled CDC or Cul de Cunard, and shorter, more densely fibered feathers usually called CDC puffs. Both come dyed in a wide range of colors as well as au natural, which is typically a light dun color. All CDC comes from on or around the preen gland of a duck or a goose.
CDC feathers have natural oils which help them to float and make them desirable to fly tiers. But it’s really their structure that’s most important. This close-up of a larger CDC feather clearly shows the teeny fibers that create surface tension and trap small air bubbles when submerged. Both help the feather to float. This close-up of the fibers on a CDC Puff shows that they’re more densely packed and not as crinkly but they still help with floatation.
Because of the larger structural differences between the two types of feathers, they have somewhat varying uses in fly tying.