I use a variety of fiber techniques in my art work, including weaving, felting, dyeing, knitting, and sewing.  I specialize in nuno-felting, where wool fibers and silk fibers are laid out on loosely handwoven or commercial sheer fabric and felted into the fabric.   The wool fibers “grab” the loosely woven or sheer fabric during the felting stage and are permanently anchored in the fabric.  If the fabric contains a significant percentage of wool, the fabric shrinks with the wool fiber, resulting in a flat combined fabric.  If the fabric contains mostly silk or plant fiber, the fabric will not shrink with the wool fibers, resulting in a softly puckered/pleated fabric next to the areas covered with felt.  I use both types of fabric, depending on the desired result.