When the silk worm is ready to become a silk moth, he hangs himself upside down in a mulberry tree and spins a cocoon around himself. These cocoons are later harvested, and as they are unraveled, they reveal the individual strands of silk. Silk is very strong in terms of tensile strength, meaning it can withstand a lot of pulling type pressure without breaking. This should not, however, be confused with wearability or abrasion resistance. Silk will not stand up to the heavy wear that other fibers will.
Silk can take on many different appearances.
A raw silk fabric may fool you into thinking that it is a cotton or a synthetic. The more refined the silk and the smaller the yarn, the more it resembles the look and feel that we know as silky. Silk is a protein fiber like wool . This gives it many of its characteristics. It is sensitive to a range of chemical situations and cannot withstand prolonged exposure to either high alkalinity or to acid or oily soils.