The fibers are unwound to produce a continuous thread. Since a single thread is too fine and fragile for commercial use, anywhere from three to ten strands are spun together to form a single thread of silk.
How to Safely Wash Silk Sheets
Raw silk from domesticated silk worms
Silk moth spinning cocoon. Google Image Result for http://imgc.artprintimages.com/images/art-print/silk-moth-spinning-cocoon_i-G-29-2910-Z1SPD00Z.jpg