Shaft construction is similar in most composite paddles. There is a major supplier in the U.S. for most paddle manufacturers. More custom shafts are appearing. Fiberglass is the most common material. Graphite is light, stiff and brittle.
Wood is warm and nice to feel.
Aluminum is cold and lasts only a short while. All shafts will have a slight or even pronounced ovalling where the hands will sit. providing added comfort and helping you know where the power face of the blade is. Care of a paddle is essential. Keep your graphite paddle out of other s hands. The high wear areas are the edges of the blades and the ferrule.