A highly valued animal fibre, silk has long been used for the production of luxrious textiles of the finest quality. Silk is produced by silkworms. The silkworm is not really a worm at a; it is a caterpillar that spins a protective cocoon for use a shelter while it change from a caterpillar into a moth. This cocoon is the source of commercial silk.Almost all commercial silk is made from cocoons spun by silkworms of the genus Bombyx. The finest quality raw silk and the highest fibre production comes from the commonly demosticated silkworm, Bombyx mori, which feeds on the leaves of the mulberry tree (morus is the Latin word for mulberry).

The whiteness and regularity of the B. mori fibre make it superior to the silk fibres produced by wild silkworm, through wilk silk fibres are also used commercially. They are produced in smaller quantities by various large, wild silkworms of the saturniid moth family, Saturniidae. Tussah, also called tasar or tussore, silk, for example, is produced by species of Chinese and Indian silkworms. Tussah silk varies in colour from brown to silver-grey. Eri silkworms prodece a white, creamy white, or reddish silk, and muga silkworms produced a golden or creamy white silk. Other types of silkworms are cultivated regionally.Silk produced by wild silkworms is generally thicker than that of the B. mori, and the coccons often cannot be reeled, or unwound.Other animals silk fibres are produced by spiders. However, these fibres are very fine and for various reasons have proved impractical for teltile use.Silk is stronger than other natural fibres. When dry, filaments are comparable in strength to such synthetic fibres as nylon and polyester .

LOOMS

Simple hand weaving was aided by hanging the warp fibers from a tree practice,believed to have led to the development of the first vertical looms. The earliest looms date from the 5th millennium BC and consisted of bars or beams that formed a frame to hold a number of parallel threads in two sets. By raising one sets of these threads, which together formed the warp, it was possible to run a weft thread between them. The block of wood that used to carry the weft through the warp is called the shuttle.One of the most significant improvements to the simple loom was the introduction of the heddle. The heddle is a device that lifts every other lengthwise thread to permit the weaver to pass the weft under a series of warp threads with a single stroke, rather than under one warp thread at a time. The space between the sets of warp threads is called the shed.

The operation of modern hand looms is essentially the same as it was for ancient looms. After the warp threads have been laid out and the ends have been attached on horizontal beams, the weaver activates the heddle by means of either a crankshaft or a foot pedal. The weaver then passes the shuttle, which contains the bobbins on which the weft thread is wound, through the shed, pushing it close to the proceeding row with a comb like device called reed. The beams that hold the cloth rotates to take up the section of cloth already produced.

The first automated loom ( the Jacquard loom) was developed by the Frenchman Joseph-Marie Jacquard in the early 1800s and formed the basis for modern automatic looms. The weaving designs into metal cards that were laced together and fed into the loom to control the weave pattern automatically.Modern power-operated have become increasingly. The most commonly used power loom is the plain loom, which is used for one-color fabrics such as those that are made into plain bed sheets. The machine consists of open shuttle that is automatically replenished by a revolving bobbin. Box looms are used for pattern requiring four to eight colors. Threads of different colors are wound on separate shuttles.

The most advanced loom in use today is the shuttle less loom. Weft threads are inserted from revolving cones and are drawn across the warp either by means of long, needle like instruments called extremely powerful, narrow jets of water.