Carbon Fibre, not surprisingly, is made of carbon crystals aligned in a long axis. These honeycomb shaped crystals organize themselves in long flattened ribbons. This crystal alignment makes the fiber strong. In turn these ribbons align themselves within long fibers. The fiber shape is the original shape of the material used to produce the Carbon Fiber. I don't know of any process where fibers are shaped AFTER carbonizing. These fibers (containing flat ribbons of carbon crystals) in turn are bundled in large numbers and are woven, made into felt, twisted or as bundled without twisting. This is referred to as Roving. Carbon fiber is also offered as chopped strands and powder.