Leather - It is sourced from Nasirabad and Raipur
Chemicals for processing - Chemicals such as lime, sodium sulphite, sulphuric acid are used to treat the raw animal hide.
Varnish or glaze - It is used to add shine and polish the final leather product.
Brass button and Buckle -
Fabric - for lining
During tanning process, substantial amount of water gets wasted. This can be recycled and put to other uses. Left-over pieces of leather can be cut into thin strips and used as stitching material for binding the pieces together. These strips are also used in braiding and making smaller products or parts of products like pocket flaps, folder binding strips, button hooks, beadings etc.
Tools & Technology
Knives - A curve edged knife is used to clean the flesh off the inside of the leather and make it even. Smaller knives are used to cut the leather pieces to workable sizes.
Palet - A blunt edged palet is used to smoothen and stretch the leather. It is shaped like a mason's tool.
Hammer - A cylindrical hammer is used to pound the wet leather to soften it.
Awl - A straight awl needle is used to pierce holes through the thick leather.
Aari Needle - A flat blunt needle is used to pull the leather strips to stitch the pieces together.
Removing the skin of the animal is called Flaying. The skins obtained are of two types, one is from the slaughterhouse and the other is removed from animals that die a natural death. The skins from the slaughterhouse can be recognized by the horizontal cut made at the neck. These are obtained in far better conditions than others. This is mainly so because animals that die naturally have to be flayed only after taking them to the outskirts of the community. This dragging and moving causes many scratches on the skin.
The skin has to be protected from putrefaction once it is removed from the animal carcass as there is often a long gap of time before the actual tanning process begins. For preserving the skin it is dried in the sun, dry salted (salt sprinkled while drying in the sun) or wet-salted (skins soaked in brine).
The tanning process prevents putrefaction and imparts durability to the leather. It also makes it firm, supple and resistant. Various types of tanning methods are employed such as vegetable tanning, mineral tanning (using Alum & salt or more recently Chromium or Zirconium salts) as well as 'Chamoising' or oil tanning (using fish oil). Even though mineral tanning is a much faster process, the most process of vegetable tanning is widely followed.
The fresh hides are first washed in plain water. The inner side of the hide is plastered with mud or salt and spread out flat. It is also sometimes held by pegs to prevent contraction. This is then dried and scraped with a blunt instrument to remove dirt particles. It is again spread flat to remove the creases and folds.
The liming process makes the hides swell to make it porous and permeable to the tanning solution. The hide is sprinkled with milk extracts of 'Aankda na phool' and with a solution of water and salt. This is done once or twice in a day, for a period of 14 days. A goat hair brush is used to spread this solution on the hide or it is done by hand. This is then folded and immersed into a pit containing the mixture. The skin is usually taken out every day, aired for an hour and immersed again.
After liming, the water is wrung out and the hide is spread on a smooth surfaced stone. The liming makes the hair fall off easily. The hair is scraped off using a blunt knife, also called Scudding. It is then soaked for 2-3 hours. Next the adherent flesh and fat on the inner side is scraped clean with a sharp knife. This step takes one whole day. After this, the hide is then put in clean running water and the lime is washed away.
Treading is done for 3-5 hours a day, while rubbing with hand is done 4-5 times. After 2-4 days, the hide is taken out and the moisture is squeezed out or alternatively it is pressed on a draining table. The hide is again soaked in a fresh and stronger solution of tannin mixture for 2-3 days. This process is repeated 5-6 times.
The hides are sewn together to the leather water bag. The tannin liquor is then poured into this bag, which is suspended on bamboo bars. This facilitates proper impregnation of the hide with tannin. The process is repeated several times after which it is done with the bag turned inside out. The hide is occasionally beaten to test if the tanning is done. If it produces a hard sound, it indicates the process is complete but if the sound is soft then the tanning is unsatisfactory.
1) Softening- The leather bag is opened out and stretched to partially dry it. It is then rolled up and trampled for some time before it is unrolled. This makes the leather compact, soft and supple.
2) Shaving- The outer side of the leather is scraped, rubbed and scoured with a knife. This process helps remove creases and the marks of the folds.
3) Polishing and Graining-The leather is now dressed with oil, mostly vegetable oil. It is applied over the leather using a smooth edged instrument or a glass bottle.
There are three methods of coloring the leather:
1) Dyeing - The leather is immersed in the dye bath until the dye penetrates. The grain pattern will nevertheless be visible through the color. Further glazing can be done using pigment or varnish.
2) Staining - In this case only the grain side of the leather is colored as it is not immersed in solution, but the solution is applied using a brush or a spray. This too can be glazed after.
3) Pigmentation - Pigment color is coated using a spray on the grain side of the skin. This forms an even surface and is used to hide flaws in the skin. In this method the natural grains of the skin are hidden. A plastic finish is obtained. Therefore, the leather is sometimes embossed with an artificial grain pattern.
4) Making bags- Two rectangular pieces of uniform thickness are taken for the front and back pieces or the body of the bag. The top edges of both are folded down. Firstly, a 'V-shaped' groove is cut on the underside along the line of the fold.
The position of the pocket is marked on one of the pieces and the top edge fold of the pocket is stitched. The piece for the pocket is dampened and stuck with rubber solution and then stitched over. A wooden mould is inserted into the damp pocket piece to help it get the sturdy shape.
The lower corners of the front and back pieces are folded at a 45 degree angle along diagonally folded upwards and then stuck. The overlap of the joining strip is marked on the sides and then stuck to both the pieces simultaneously. The right-angled triangles at the base are stitched along the sides of the triangle. The shoulder strap too is first marked and then stitched in a rectangular form. It is stitched with two crossed lines to add strength.
According to the design requirements, the technique of braiding is used in the leather products in the form of braided straps or embellishment. The basic principle of braiding is the overlapping of a number of linear strips with each other in one plane. Each strip rides over the two consecutive strips, and goes under the third one. This is done alternatively with strips from both sides. There are three types of braiding done:
1) Flat braiding - In this type, the minimum number of strips used is three and many more can also be used. For greater variations in patterns, more number of strips is used.
2) Circular plaiting - The minimum number of strips used is four. As the number of strips increases, the circular tubes become wider and forms cylindrical shapes that can be used in making dog leashes, whips, decorative cover for cylindrical objects etc.
3) Square or solid braiding -The outermost strip is crossed over its own group and the next two groups, then threaded under the last group it has crossed over, ending in the center of the strands. In this manner, an enclosed solid braid is made which is flexible in both directions.