Context: In forensic science, fiber evidence can be used to trace evidence from a crime scene to an offender responsible for a crime. The main problem with fiber testing is that it can be very difficult to identify an offender as most fibers do not have a clear difference between them. Fibers can be classified as natural, synthetic or semi-synthetic based on the fiber formed. A natural fiber is produced entirely from a plant or animal. An example of a natural fiber is silk, accidentally discovered by the Yellow Emperor's wife, Hsi Ling Shi. According to legend, a cocoon fell from the tree above her and unraveled, allowing her to discover the Bombyx mori silkworm. After its discovery he developed the cultivation of silkworms called sericulture (History of Silk, 2012). China had a monopoly on the silk trade for thousands of years and organized the Silk Road; which expanded the trade of silk and other products throughout the world. Silk was not available in America until the 17th century, and today its major producers include China, Japan, India, and Italy (Silk Painting Gallery, n.d.). Silk was used for clothing production, musical instruments, bow making, and as decorations in upper-class families (Silk Road China, 2013). Silk can be produced by other insects, but moth caterpillars are the main contributor to silk textile production as they create a much smoother and finer fabric (Silk History, n.d.). The cocoons are raised by the farmer and delivered to the factory, or spinning mill, where the silk is unwound from the cocoons and the threads collected into spools. When the spinning mill receives the cocoons it must select them based on color, size, shape and consistency. Then they put t... in the center of the paper... and react to form a prepolymer. In the production of dry spinning fibres, the prepolymer is additionally reacted with an equal amount of diamine. The resulting solution is diluted with a solvent to produce the spinning solution. The dry spinning solution is pumped into a spinning cell where it is converted into fibers by forcing the polymer solution through a spinneret. This causes the solution to be aligned into strands of liquid polymer. As the wires pass through, they are heated in the presence of nitrogen and solvent gas, causing the liquid polymer to chemically react and form solid wires. The fibers are then treated with a finishing agent that prevents the fibers from sticking together. The fibers are transferred through a series of rollers onto a spool. When the spools are full they are put into final packaging and shipped to textile manufacturers and customers.