Major Types of Fibers

Cotton
Cotton is the most commonly used plant fiber in production, with almost all clothing containing some amount of manufactured cotton. The type, length, and color of the identified cotton fibers are significant in narrowing the search to one textile producer. From there, the rarity of the fiber can be considered and statistics can determine the odds in which the cotton found at the crime scene belonged to a suspect.


Wool
Wool from sheep is the most common animal fiber found at a crime scene. The coarseness of the wool is a large factor in determining the origin of the fiber. Fine wool is used for clothing while the coarser strands of wool are used in carpet production. Other wool fibers from less common sources (such as a camel) can drastically increase the rarity of such fibers and therefore minimize statistical odds.



Nylon
Nylon is a very common synthetic fiber first used as a replacement for silk. Because of the wide range of uses for nylon (carpeting, musical instruments, clothing, and rope) the ability to identify a rare source is somewhat reduced. However, rope fibers at a crime scene are often matched to a suspect's rope in murder or kidnapping cases. The color and other properties of the nylon can help identify their use and therefore a source.

Silk
Silk is most often used for clothing made from extracted silkworm fibers (Bombyx mori). Silk isn't a very common fiber, which makes it easier to pinpoint a manufacturing source and determine the rarity of the substance. The chemical and physical properties of silk are very unique, as silk has an easily identifiable texture and is one of the strongest natural fibers in the world.





Linen
Linens are used in clothing and are valued for their ability to maintain their coolness in a hot climate. Linens are used to produce a variety of items like aprons, towels, bags, bed sheets, tablecloths, napkins, and clothing. The use of the sample can be determined by the length of the fiber. If the fiber is short, it is used for coarser fabrics, whereas longer fibers are used for fine fabrics. Since linens are an expensive textile, linen fabrics are produced in small quantities. This makes it a lot easier to find a source and a suspect because of the rarity of such material.