Silk is another fiber that is blended in yarns offered by Worsted Spinning New England. Cultivated Silk, also called Bombyx silk or Mulberry silk, is 10-13 microns and bright white and lustrous, produced from silkworms in captivity that feed only on mulberry leaves. We also carry tussah silk or wild silk, which is a bit stronger and more durable—these worms eat oak leaves and the oak tannin stains the silk a soft beige to beautiful golden brown color. Micron count for Tussah silk is between 26-36.