Combed singles yarn sailcloth in high counts is used for spinnaker and head sails. The count often is 148 by 160 and the fabric is finished at wide with a length-to-mass ratio of about 13.10 m/kg (6 yd/lb). The quality and weight of the weave can be more critical than the choice of fibers, since a poor weave can lead to high stretch and poor sail form. Weight is described in ounces, for example "an 8 oz. cloth". This means that an area of weighs .