The unbalanced nature of the thread used in these towels helps give it an additional pattern.
Yarns that are overspun or underspun (either commercial or handspun) tend not to lie flat when woven in a plain weave. Often, diagonal hills and valleys will appear in the weave. This is called tracking; and can be used to great effect, adding interest to a fabric.
The warp and the weft for this towel is a 6/2 unmercerized cotton. The colors used in this plaid are a pale mustard and a sage.
Below is a close up view of the weave structure. This is a simple plain weave. The pattern requires 2 harnesses, and the sett is 18 e.p.i.