Jib

Either clipped to the forestay with piston or soft hanks and hoisted on the jib halyard, or — the usual cruising arrangement — fed by its luff tape into the grooved foil of a roller furler, where it lives permanently and rolls away on the furling line.

Cut with an LP (luff perpendicular — the shortest distance from the clew to the luff) of roughly 100% of J or less, so the clew stays inboard of the mast and rigging. Racing shorthand calls a full-hoist non-overlapping headsail the #3 or blade, typically with an LP in the 100–110% range. Woven polyester is the norm on cruisers, with a foam or rope luff pad on furling versions to keep some shape when partially rolled.

Trim with the jib sheets and set twist with the jib car position: cars forward close the leech and power up, cars aft open the leech and depower. Steer or trim to the luff telltales — both streaming aft means attached flow. On modern fractional-rig boats a roughly 100–110% jib is simply the headsail for all conditions, with power coming from the big mainsail; in a masthead boat's inventory the jib is what you change down to when the genoa becomes too much, typically somewhere near 18 knots and up — boat-dependent, as always.