Sheet

According to Wikipedia, in sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) (clews) of a sail. In practical yachting, sheets are essential running rigging components that control sail trim, shape, and angle of attack relative to the apparent wind. Unlike halyards, which hoist sails vertically, sheets control horizontal position and leech tension. The primary types are the mainsheet (attached to the main boom or clew) and jib or genoa sheets (attached to the foresail clew).

On modern sailing yachts between 30 and 50 feet in length, sheets are constructed from low-stretch braided polyester or Dyneema core ropes with diameters typically ranging from 8 to 14 mm. Proper line diameter balances tensile strength, friction in blocks, and hand comfort. During maneuvers such as tacking and gybing, sheets are eased and trimmed continuously. Safe execution relies on correct yacht rope handling around winches and sheet stoppers.

In English terminology, it is vital to distinguish the nautical noun "sheet" from homonyms such as bed sheets, sheet metal, or paper sheets. In seamanship, a sheet is strictly a control line, never a sail itself. Accurate sheet trim prevents sail stalling and optimizes aerodynamic drive.