Abstract: A hook member is provided that is capable of engaging fibers. The hook member includes a stem extending upwardly from a sheet-form base to a distal end. The stem has leading and trailing edges that form an apex angle therebetween. A crook is integrally formed with and arches along a curved axis directly from the stem of the hook member to a tip. The crook has a width measured along a line tangent to the tip and perpendicular to a central axis that bisects the apex angle and intersects a plane substantially parallel to the sheet-form base that is less than about 20 percent of a height of the hook member measured along a line extending perpendicular to the base.