Many spinners differentiate between worsted preparation and worsted spinning. Worsted preparation refers to the way the fibre is prepared before spinning, using ginning machines which force the fibre staples to lie parallel to each other. Once these fibres have been made into a top, they are then combed to remove the short fibres. The long fibres are combined in subsequent gilling machines to again make the fibres parallel. This produces overlapping untwisted strands called slivers. Worsted spinning refers to using a worsted technique, which produces a smooth yarn in which the fibres lie parallel.