Silk, also known asthe queen of textile, luxury, elegance, class, and comfort. The silkworm that spins a protective cocoon around itself as shelter while it changes from a caterpillar into a moth produces this high value animal fiber. The cocoon is the source of commercial silk. Silk fiber has qualities like natural sheen, inherent affinity for dyes, high absorbency, lightweight and excellent drape. Chemically , silk is made of protein secreted in fluid state by the silkworm.
There are four main different varieties of silkworms :
1. Mulberry silk
Light yellow colored, finest silk obtained from silkworms that feed on mulberry leaves only.
2. Eri silk
Multivoltine silk is spun from open-ended cocoons. A silkworm of Eri silk eats only castor leaves. The color of silk is creamy white.
3. Muga silk
This golden colored silk is obtained from silkworms that feed on the aromatic leaves of Som and Soalu plants.
4. Tussar silk
Copperish in color, this is coarse silk generated by the silkworm Antheraea mylitta, that thrives on the plants Asan and Arjun. The rearing of this silkworm is conducted naturally on trees in the open, so this is also known as wild silk.
History of Tussar Silk
The origin of the craft is not known but it was observed after the 16th century when the first European merchants came to India and surveyed the craft. Four varieties of tussar fabric were mentioned; these were mainly cotton-mixed fabrics. The weaves and colors were very simple at that time. In Indian tradition, saris of silk are considered very pure, especially saris made up of reeled cocoon, which has not been spun. Another type of fabric known as Mukta, is popular among the Jain community. Here the moth has cut through the cocoon and escaped, leaving the silk filaments as a mass of short fiber, which has to be spun.
Both home furnishings and dress material are made from tussar fabric. Under home furnishings, products are cushion covers, pillow covers, curtains, etc. For apparel, the products are scarves, shawls, saris, dupattas, and running material.
The craftsmen involved in this craft come mainly from communities such as Muslims, Scheduled castes and some local tribes. This craft is the major source of income for the families of nearby villages. Both women and men are involved in tussar silk production.
Bihar produces about 66% of Indian tussar, although these days much of it is woven in other states such as West Bengal and Odisha. The Bihar town of Bhagalpur is world famous for its tussar handlooms.
Designing and Weaving
The first step of tussar weaving involves designing. The master craftsmen select the drawings. The design is mainly variations of weave and color. The next step is raw material preparation which is a long process consisting of the following steps:
Cocoons are firstly sorted and then the good ones are boiled in water with some amount of soda for 1/2 to 2 hours. For 1280 cocoons, 300gms of soda is used. In this process, the vessel is pressed with a heavy lid, so that the cocoons do not come out. After boiling, the silk strands are unwounded onto bamboo spools.
Workers use their bare thighs to draw out a single filament of silk from the cocoons. This silk is known as ghicca silk. In khewa silk, the hands are used to unwind the silk filament
After this process the spools are transferred to skeins. After drying, these skeins are reeled on bobbins to make a thicker, stronger, and multi threaded yarn. Around 10 skeins are twisted together.
Natural dyes are commonly used for dyeing tussar silk. While the process of dyeing is similar for all colors, mordants are used differently for specific colors. In general, the first step for all dyes is extraction by boiling the dyestuff in water. The solution is strained, and the dye is applied to wet yarn skeins. After some time the skeins are put in mordant solution to fasten the effect of the dye. The last step is to wash the yarn with reetha powder. For black color harer powder is boiled in water for 15-20 minutes. The wet skeins are put in a dye bath for 20 minutes in a separate container.
Kasis stone is used as the mordant. It is put in plain water and sieved. The dyed skeins are put into this kasis solution for 5 minutes. After 20 minutes the skeins are washed in reetha solution. For indigo dye the mordant (alum) is applied before dyeing, and the skeins are kept in an airtight container. After half an hour, the skeins are put into boiling indigo solution. The excess dye is washed out with reetha.
In the weaving operation, lengthwise yarns that run from the back to the front of the loom make the basic structure of the fabric and are called the warp. The crosswise yarn is the filling, also known as weft. Before weaving the warp and weft yarn needs to be spun to the required specifications. Then the yarn is wound onto large spools, which are placed on a rack called a creel. From the creel, the yarn is wound onto the warp beam. This process is known as spooling.
In the weaving process on the loom, the warp beam is mounted at the back and the warp yarns are conveyed to a cylinder called the cloth roll, which is at the front of the loom. Supported on the loom frame between the two cylinders, the warp yarns are ready to be interlaced by the filling or weft yarns, to produce the woven fabric. In the weaving process four steps are fundamental –
Shedding: the operation performed by the harnesses – rectangular frames to which a series of wires, or heddle, are attached. As each warp yarn comes from the beam, it must pass through an opening in the heddle.
Drawing in: the operation of drawing each warp yarn through its appropriate heddle eye. . In the weaving process the heddle frame raises or lowers certain groups of alternate warp yarn by treadles, so that the filling yarns alternate in passing under one group of warp yarns and over another.
Picking: As the harnesses raise the heddles, which in turn raise the warp yarn, the filling yarn is inserted through the shed by the shuttle that contains a bobbin of filling yarn.
This crossing of wefts between the shed of the warp is known as Picking.
Each warp yarn passes through a heddle eyelet and through an opening in another frame that resembles a comb and is called the Reed. With each picking operation, the filling yarn is pushed against the woven fabric. This process is known as Beating.
With each shedding, picking and beating, the newly constructed fabric must be wound on the cloth beam. This is referred to as taking off.
After the fabric is taken off the loom, it is washed with plain water and spread for drying. After drying, water is sprinkled with a spray machine. This spraying should be uniform all over the surface. Then the fabric is folded properly and beaten with a heavy hammer, called kundi. This beating process sets the weave properly. The fabric is now ready for calendaring. This is a mechanically produced finish, achieved by pressing the fabric between a series of two or more rollers to smoothen it and produce a wrinkle free effect.