Editing Sail components (section)

===Reinforcements at attachment points===
[[File:Kopfbrett1.jpg|thumb|''Headboard'' on a mainsail.]]
The corners of triangular sails are typically areas of high stress and consequently often have reinforced layers and tape radiating from, whether cross-cut or radial in construction. Their corners are always attached to a [[shackle]], attached to a line or spar—the [[halyard]] at the head, a shackle at the tack, and the [[outhaul]] at the clew. The connecting shackle runs through a [[grommet]] at each of these points. There are additional points where reinforcing and grommets may occur: at the [[Cunningham (sailing)|cunningham]], a [[downhaul]] used to flatten a mainsail (jibs may have a similar feature), and along the foot of a [[Genoa jib]] to allow a line to lift it out of the waves. The head of a triangular sail may have a rigid ''headboard'' riveted to it in order to transfer load from the sail to the halyard.<ref name = Colgate/>

Square sails and gaff-rigged sails also have grommets at corners. Only the clews on a square sail take a comparatively large amount of stress, because the head is supported along the spar. Three sides of gaff-rigged sails are attached to a mast or spar.{{sfn|King|Hattendorf|Estes|2000|page=146}}