The softest and most comfortable sling you'll even own. Twill fabric is heavier than plain weave linen with a more structured form. These qualities give it the remarkable durability characteristic of twill materials as well as wrinkle and stain resistance. This fabric is marked by its distinct diagonal pattern. The twill technique involves the weft yarns wrapping around at least two warp yarns at a time in a unidirectional pattern that creates diagonal lines in the fabric.