All yarns are initially spun as single plies. In the ancient Peruvian textiles, there are evidences of preferences for single-ply yarns or at least the use of them even in fabrics we should consider called for heavier elements. The Chincha domestic cloths are good examples. We made yarn analyses on half of the total number of cloths in the study. All but ten of the fifty-seven examined were woven with single-ply warp and weft elements and of these ten, only one coarse cloth had 2-ply warps and wefts; the remaining nine had 2-ply warps crossed by single-ply wefts. The majority of these fabrics classified as "fine" weavings.

Yarns may be twisted (spun) in two directions. The spirals formed by twisting may extend upward to the left (the S-twist) or to the right (the Z-twist). The frequencies of the left and the right twist in yarns are indicative of motor habits, if nothing more.

The largest Chincha group comprises twenty-nine cloths in which the warp and weft elements have left spirals; a much smaller group (5 specimens) shows yarns with right spirals. Two other groups (6 and 3 pieces, respectively) have warps with left spirals crossed by wefts with right spirals and vice versa. The other cloths in which yarns with different twists are combined perhaps may represent the use of odds and ends of yarns. The following combinations were found:

1. Single-ply S-twist and Z-twist warps crossed by single-ply S-twist wefts (2 specimens) or crossed by single-ply Z-twist wefts (1 specimen).

2. Single-ply S-twist warps crossed by single-ply S-twist and Z-twist wefts (1 fine-texture specimen).

Yarns are characterized as soft- or slack-twist, medium-twist, hard- or tight-twist, with various intermediate degrees depending upon the angle taken by the spiral in relation to a vertical axis. A 25-degree angle, for example, characterizes a medium-twist yarn tending toward hard-twist. Yarns with 30-degree to 45-degree angles of twist are hard-twist yarns. More than half of an unselected sample of twenty yarns fell within the 25-degree to 45-degree range. The remaining seven had angles from 50 degrees to 90 degrees in some sections of their lengths. An idea of the variations in any one weaving element may be gained from plate 4,c and the enlarged section of fabric in plate 7,c.