Velvet is woven on a special loom that weaves two thicknesses of the material at the same time. The two pieces are then cut apart to create the pile effect, and the two lengths of fabric are wound on separate take-up rolls. This complicated process meant that velvet was expensive to make before industrial power looms became available, and well-made velvet remains a fairly costly fabric. Velvet is difficult to clean because of its pile, but modern dry cleaning methods make cleaning more feasible. Velvet pile is created by warp or vertical yarns and velveteen pile is created by weft or fill yarns.