Abstract: An unpredictable random distribution of segments of supplemental strands of fiber are produced in a base strand by pulling segments from the supplemental strands and adding them to the base strand. The segments are pulled from free extents of the supplemental strands that have a free length longer than the length of the fibers of the supplemental strands, and the supplemental strands advance slower than the base strand, with the result that the size and occurrence of the pulled segments in the base strand are unpredictably random. Preferably, a draw frame is used, to which is added a feed unit having a pair of rotating feed rolls for feeding the supplemental strands to the next-to-last pair of drafting rolls that have a surface speed greater than the feed rolls and are spaced therefrom a distance greater than the length of fibers in the supplemental strands.