Abstract: A continuous yarn structure comprising at least one yarn element formed from a plurality of continuous filaments or a plurality of staple fiber lengths, the yarn structure comprising periodically repeating lengths of high bulk, substantially unentangled continuous filaments or staple fiber lengths alternating with lengths of compacted continuous filaments of staple fiber lengths in which substantially all filaments or fiber lengths are mutually entangled throughout the volume of the compacted lengths.Also disclosed is a method for producing such yarn. The method comprises the steps of feeding at least one multiple filament yarn element or multiple staple fiber element under tension to a first treatment zone having a predetermined cross-sectional area; continuously directing a fluid at the yarn element in a direction substantially perpendicular to the travel of the element, the fluid being applied at a pressure of at least about 100 p.s.i.