Aside from stitching styles, a key distinctiveness in Bohai Mohe embroidery lies in the material. Most southern Chinese silk is cultivated from the cocoons of bombyx mori, a domesticated moth that feeds exclusively on mulberry leaves. However, Sun Yanling uses Tussah silk, collected from antheraea pernyi moths that live in the wild. Their larvae feed on oak tree leaves, which are more widespread in northeastern China. The resulting Tussah silk is thicker, coarser, and stronger, with the potential to last hundreds of years.
One Tussah silk floss contains more than thirty strands of silk, but the standard is to divide the floss into sixteenths that are thinner than a hair’s width. Using a tiny needle, it takes Sun about three months to complete one artwork, depending on the scale and complexity.