Fiber preparation can be done at home with handcarders or a drumcarder for small amounts of fiber. For larger amounts, you can send the fiber to a professional mill to have it cleaned, carded, and combed. Carded fibers from a mill are called batts, rovings, or slivers. Combed fibers are called tops.
Carded Fibers
Carded Fibers produce soft, lofty, woollen yarns suitable for knitting.
Batts are large, soft, rectangular forms of wool. Putting layers of wool through a drumcarder several times, will produce small batts of fiber.
Slivers (commercial) are ready-to-spin strips of fiber. Slivers can also be made from handcarded or drumcarder fiber.
Rovings are similar to slivers but a little smaller in size.
Pencil Rovings have the width the size of a pencil, and are already pre-drafted for handspinning.
Rolags are small rolls of fiber that are carded with handcarders.
Combed Fibers
Fibers produce strong, smooth, worsted yarns suitable for weaving.
Combed Tops are the result of fiber that is combed to remove the short fiber and to keep the long ones. The fiber strands are always kept parallel to one another during the process. Tops can also be made at home, by using Dutch combs or mini combs and a diz.