User:Davidbena/sandbox/Comparative Chronologies

Primitive tanning are the techniques practised of old, throughout the world, in curing and tanning leather, before the introduction of chemical agents used in the modern tanning industry. Primitive tanning methods, almost exclusively, made use of natural or vegetable tanning agents, while chrome tanning was unbeknownst to tanners. Even so, the methods employed by these tanners differed from place to place, and the resulting leather product often depended on the people's needs, whether it was for clothing, shelter, means of transport or for writing purposes. So pervasive were the differences between regions and countries that thirty-six different native vegetable tanning materials were known to have been used throughout the British Empire.

In some societies, a process known as "tawing" was used instead of vegetable tanning, which produced a faster-made pseudo-leather product, was considerably softer and lighter in weight, but which left a "leather" product less durable in the wet state. In a technical sense, this process was not considered tanning, par excellence, as the proper steps had not been taken to turn the rawhide into durable leather.

Europe
One of the earliest records of curing leather in Europe is contained in the book Homer's Iliad (389 f.):

"The ox hide, which is soaked in fat, is pulled to and fro by men standing in a circle, thus stretching the skin and causing the fat to penetrate into the pores."

Later, in Western societies, preparation of a rawhide for use usually followed a procedure of salting, flouring (drenching) and tanning with a tannin, which latter was derived from gallnuts, or similar substances having tannic acid. Salting is the first step in the tanning process which is applied to the flesh-side of the rawhide. Salting acts to preserve the rawhide if it is to be kept over for a prolonged period. The salt also acts to draw out the blood trapped in the follicles.

Maimonides (1138–1204), who called for salting, flouring and tanning in succession, required rubbing down the rawhide with flour (presumably barley flour), although Simeon Kayyara (8th century), in his Halachot Gedolot, required flour being placed inside a tub of water, into which the raw hide was inserted and left for a few days. The action of the flour-based liquor, or what is also called drenching, served to soften the hide. The best flour was considered the bran obtained from barley grains.

A common practice in European societies, after the removal of the fat, flesh and subcutaneous tissue that cling to the flesh side of the hide, was to immerse the untreated animal hide into tanning liquors with crushed plant parts containing tannins. In Northern Europe, this was usually bark procured from oaks, birch, willow, spruce, and larch, whereas in southern Europe tanners often made use of sumac leaves, valonia bark, acacias and oak galls. During the tanning process, raw skin is transformed to leather. In some cases, as in the hides of cattle, the skins that are treated with ground oak-bark can remain in the pit as much as one year before turning into leather. After tanning, the hide can be made into its desired thickness by either shaving, such as with a pumice stone or skiving knife, or by splitting the leather.

In the late Roman era, animal skins were rendered soft and pliable by rubbing them against the surface of a stone pillar or column.

Middle East
In Palestine in the 2nd century, the typical method of dressing leather (with the hair intact) began with salting the rawhide. Bedouins often poured salt on the flesh-side of the hide, rolled up the hide with the salt, placed it in a sack and stored it away on a tree branch for long periods, until its owner was ready to work the leather. If the hair was unwanted, it was first removed before salting, usually by inserting the entire rawhide into a lime-bath solution for approximately 4 days, or the duration of time needed for the hairs to loosen and fall off.

Fleshing of the rawhide to remove subcutaneous tissue was one of the primary steps, usually accomplished with the aid of a rasp. Afterwards, the rawhide was salted, followed by a treatment in flour (either rubbing or soaking). This is followed by applying tannins to the rawhide, such as pulverized gallnuts or the green and ground leaves of sumac (Rhus coriaria), applied with a little water to both sides of the hide, and repeated as needed. The application of tannins to the rawhide constricts the fabric and converts the rawhide into durable leather. Tannins derived from the rinds of pomegranates (Punica granatum) or from the leaves and bark of Pistacia palaestina were also used to tan skins.

In Yemen and in Egypt, the tannin of choice were leaves obtained from the Acacia tree (Acacia etbaica), but instead of applying the powdered leaves to the rawhide, a bath solution was made from the crushed leaves and the rawhide inserted within the bath, which remained there for up to two weeks. The water was stirred on occasion and changed after one week, with a new batch of Acacia leaves added.

The final process, after tanning, was to rub the tanned hide back and forth against wooden posts or marble columns in order to soften and smooth the grain of the leather.

In Arabia, camel hides were cured by treating them with a species of Calligonum. The hide is first rubbed with salt and with wheat dough. The hide is then rolled and left in such a state to cure in the shade for 5 days. Afterwards, the hide is unrolled and cleansed of its salt and wheat dough, when fleshing of the hide is then commenced. Afterwards, Calligonum comosum (known locally as arṭā) is applied to the hide, to complete the tanning process, followed by stretching of the leather to make it pliable.

West Africa
After fleshing the animal, hair removal on the rawhide or skin of the animal was achieved by soaking the hide in a bath solution containing the wood ashes of Anogeissus schimperi, followed by a bating bath composed of a decoction of a plant known as serri in the local parlance, or what is Daemia cordata (syn. Pergularia tomentosa). After scraping, pulling and stretching to render it soft, pliant and absorbent, the skin was typically tanned by making use of either acacia pods (Acacia arabica) or chips of mangrove bark. Among the Hausa of Nigeria, in preparation for dyeing the leather, two tubs of a bath solution were provided for the leather hides, after first rubbing the tanned surface of the leather with a cloth dipped in either ground nut oil, palm oil, or shea butter. The first tub contained a bath of ash water procured from burnt wood (preferrably the hard wood of Anogeissus schimperi), which water and ash mixture are left to sit undisturbed for about 3–4 hours, and later, the pulverized red leaf-sheaves of sorghum (Sorghum guineense) that had been prepared in a separate container are added thereto. The rawhide is then inserted in this tub with its solution of ash water and sorghum leaf, which action began the dyeing process. After soaking and treating the leather with a dye solution, the rawhide is taken out, wrung out by twisting it taut between two poles, and then submerged in a second tub containing cold water which has been acidulated with lime juice, or in cold water in which tamarind pulp (Tamarindus indica) has been macerated; the pods, complete with seeds and pulp and gradually warmed by a fire. The hide is left there for a few hours. The hide is then taken out of the liquor and is then exposed to the air by hanging it out to dry. When dry, the hide is continuously rubbed with a smooth stone while it is draped over a wooden block.

Leather that has been tanned with the pods of the acacia tree (Acacia arabica) has a dark reddish-brown hue.

East Africa
In Ethiopia, when sheep, cattle or goats' hides were to be used without the animal's hair, tanners would first soak the rawhide in a salt solution until clean. The rawhide was then taken out and the fleshing process began, to remove all subcutaneous tissue. A paste of sour-dough (flour) was then applied to the flesh-side of the hide and left to dry. Afterwards, the hide was taken up and inserted into a tub of plain water, and left there to soak. The hide was then removed from the tub while the sour-dough still clang to the hide, stretched and spread-out on the ground while secured to stakes. When dried, the sour-dough was scraped away and a new batch of sour-dough applied to the rawhide. Hide is left to dry in a shady place. The process of dehairing then began, followed by the tanning process itself. After the hide was cleansed from all residue of hairs and the sour-dough paste, the shredded, green leaves of the castor-bean plant (Ricinus communis), known in Amharic by the name bulqah and in Tigrinya by the name qul'ee, was applied to both sides of the hide. The green leaves of this plant remained on the hide until they completely dried out. Afterwards, the residue of dried leaves were removed and the hide rubbed down with an oil extract taken from the castor bean itself. Flour is added to the leather to absorb any excess oil. This process produces a white leather.

For gazelle, deer and antelope where their hides contract after flaying, the hides are first fleshed of all subcutaneous tissue, and then stretched and held down with pegs, flesh-side up. Table salt was spread over the flesh-side while the hide remains in a hot sun for 3 days, so that the sun's effects, which ordinarily causes the hide to shrink, causes it to dry in a stretched-out position, without contracting. The salt has the added effect of preventing the rawhide from becoming worm-infested. After removing all traces of salt, a mixed paste of ground Niger seeds (Guizotia abyssinica), known in Amharic has nūg, and ground Flax seed (Linum usitatissimum), known in Amharic as talvah, are spread in heaping portions upon the flesh-side of the hide, and left to dry in that condition for a few days. (The seeds are slightly roasted before they are ground into a flour and made into a paste or gruel by mixing with water). Afterwards, the paste (which carries natural oils and which are released with the addition of hot water) is worked into the hide. This is achieved by rolling the hide and stomping on it while the paste clings to it, as well as by rubbing the hide between one's fingers and knees, working it continuously, until, at length, one is left with a soft leather. The curing of these hides was done entirely without the use of tannins, similar to the use of brain in the production of buckskin leather.

Asia
In Japan, tanning with brain-matter and smoke was also practised of old. Its mention is found in a late record edited by Fred O’Flaherty, and published in 1956 in Chemistry and Technology of Leather: "To prepare Koshuinden leather, one starts with dried deerskin which has been soaked to the extent that the grain layer, together with the hair can be shaved away with a skiving knife. Tanning is accomplished by coating with animal brain matter or spinal-cord substance, for which mechanical tumbling, kneading, and staking probably are indispensable. A smoke tanning now follows, according to the description of Sawayama..."

North America
In North America, the treating of leather taken from deer, elk, and buffalo, etc. was primarily performed without tannins, but rather by an application of brain matter, stretching, and smoking after the hide had been thoroughly fleshed of all fatty and subcutaneous tissue. The end product was Buckskin, which is still a raw skin that has been made supple and soft by breaking up the fibers mechanically and has then merely been treated with brains and smoke to preserve its softness.

[REVISE] Deerskins were the most commonly tanned, worn and utilized skin because of their durability, softness and availability. They were the basic “fabric” of pre-historic times. Other animal skins were also tanned using variations of the brain tanning process, (buffalo, moose, elk, antelope, caribou, bighorn sheep). Even furs were tanned using brains and woodsmoke, though they were handled differently to prevent the hair from slipping out.