Abstract: A method and apparatus for forming a yarn or sewing thread from core and effect yarns. The effect yarn is drawn at no higher than a normal drawing ratio for material from which the effect yarn is made and the effect yarn is softened by sufficient heating, in order to prevent rupturing of the effect yarn during drawing. The core or effect yarn is passed through a wetting device to aid aspiration and entanglement of the core and effect yarns in a fluid jet device. The effect yarn is overfed to the jet device to aid in the formation of a highly entangled looped yarn which is subsequently set by a heated roller while contraction of the yarn is prevented. The core yarn can also be drawn at or below its normal drawing ratio in order to aid in developing thread tenacity and ensure an acceptable elongation at break after dyeing or subsequent wet processing.