Put simply, fly dubbing is the material applied to the tying thread when it's wrapped over the hook in the fly tying process, creating the 'body' of your fly when fly tying.
To be 'dubbed' simply relates to the twisting motion required in application of fly tying dubbing to the thread.
Fly tying dubbing comes in many types of different dubbing materials and colours and can be blended for extra affect.
When fly tying with dubbing materials the tier needs to twist the dubbing materials onto the thread.
With natural fly tying dubbing like rabbit and other animal fly tying materials a dubbing wax may be needed.
When fly tying, dubbing is mostly used as a body material for both nymphs and dry flys.
When choosing tying dubbing for dry fly choose a dubbing with natural oils like seals fur, rabbit or possum so they float well and do not become water logged.
Different fly tying dubbing like Ice dub is a synthetic blend with natural tying dubbing or just synthetic dubbing materials.
Learning to dub is an important process when fly tying.
Tying your own flies for fly fishing will enhance your fly fishing experience.