SHAGREEN, or CHAGREEN, is the name of a kind of grained leather made in Astracan by the Tartars and Armenians, and much prized for forming covers for cases, books, Sec. It is a close and solid sub stance, covered over with papilla or little roundish grains. The following method of preparing it is a brief abstract of the method described by Professor The hinder back piece of the hides of horses and asses is cut off immediately above the tail, in the form of a crescent. The only part that is useful is about a Russian ell and a half across the loins, and a short ell along the back. The skins thus cut are soaked for several days in pure water till the hair drops off. They are then extended, and the hair and epidermis removed with a scraper. After a second soaking the flesh side is similarly scraped, and the whole cleaned till nothing but the pure fibrous tissue remains. The skins thus prepared are stretched in a wet state on wooden frames, with the flesh side down wards, and over the upper side are scattered the hard, black, and smooth seeds of the chenopodium album, or goose foot. A piece of felt is then spread over them, and the seeds are trodden into the leather. The frames arc then placed against a wall with the seedy sides next it, and in this way they are perfectly dried. When the unpressed seeds are beaten otT, the skin is full of indentations, which produce the grain of the shagreen.
The dried skins are next scraped with a piece of sharp iron bent like a hook, till all the inequalities are removed, and this process is repeated with a finer scraper till only faint impressions of the seeds re main.
In this condition the skin is put into water for 24 hours, and the effect of this is to swell the faint im pressions of the seed, and raise it above the surface acted upon by the scrapers, a considerable part of which has been removed. The depressed parts which have lost none of their substance being thus elevated, constitute the grain of the shagreen.
The skins are now immersed several times in a strong warm ley, obtained by boiling a strong alkaline earth called schora. They arc then piled upon one another while warm, and in some hours they swell and become soft. They are afterwards rendered exceed ingly white and beautiful by 24 hours immersion in a strong pickle of salt.
The next step in the process is to give the skins their final colour. The following is the method for the most common colour, which is sea-green. Let the skins, when taken from the pickle, have their flesh or unprepared sides well washed with a saturated so lution of sal ammoniac. A thick layer of copper filings is then strewed over them. Each skin being rolled up in a piece of felt, the rolls are all laid together in proper order, and pressed down for 24 hours by some heavy body. During the time the sal ammoniac has dissolved a sufficient quantity of the coppery par ticles sufficient to give the skin a sea-green colour.
In order to give the blue colour, two pounds of finely powdered indigo are dissolved in cold water. Five pounds of pounded alakar, or crude soda, is then dissolved in it, along with 2 lbs. of lime and 1 lb. of pure honey. The whole is put several days in the sun and often stirred. The skins to be dyed blue are to
be moistened only in the strong ley of schora, and not in the salt brine. When moist they are filled up and sewed together at the edge, the flat side being inner most, and they are dipped thrice in the remains of an exhausted kettle of the same dye, the superfluous dye being each time squeezed out, and after this process they are dipped in the fresh dye prepared as above, which must not be squeezed out. The skins when dried and pared are finished.
In order to make black shagreen, the skins when moist from the pickles are thickly bestrewed with pul verized gall nuts, and then folded together and laid over each other for twenty-four hours, Each skin is next dipped several times in a new ley of the schora, after which they are again bestrewed with rounded gall nuts, and placed in heaps till the galls have tho roughly penetrated them. When freed from the dust of the galls by beating, they are rubbed over on the shagreen side with melted sheep's tallow, and exposed to the sun to imbibe the grease. When the super fluous particles have been scoured by a blunt wooden scraper, and the skins have lain some time, the sha green is moistened on both sides with a solution of sulphate of tin, by which it receives a beautiful black.
In order to make white shagreen, the skins are first moistened on the shagreen side with a strong solution of alum, and then daubed over on both sides with a paste made of flour. The paste, when dried, is wash ed off with alum water, and the skin is then dried in the sun. When the skins have imbibed sheep's tal low, as described in the last paragraph, the super fluous fat is scraped off with a blunt wooden instru ment, when the skins are wet with warm water.
This white shagreen is intended for receiving a dark red colour. In this case the skins must not be immersed in the solution of schora, but after being whitened they are washed in the pickle of common salt for 24 hours. About a pound of the best dried tschagann, (saloia iricoides,) is now boiled a full hour in about four common pailfulls of water, which thus acquires a greenish hue. The herb being taken out, half a pound of pounded cochineal is put into the ket tle, and the liquor boiled a full hour with frequent stirring. About 15 or 20 drachms of orchil is added, and after a little more boiling the kettle is removed. The skins taken from the pickle are then placed over each other in troughs, and the dye liquor is poured over them four times, and rubbed into them with the hands. The liquor is expressed each time, after which they are dried, and are much more valuable than any of the other kinds of shagreen.
Shagreen has sometimes been made of the skins of fishes, such as the angel fish, the greater dog fish, and the sea call*.
The best shagreen is that which is brought from Constantinople, which is of a brownish colour; the white is not esteemed good. Shagreen is frequently counterfeited by Morocco, but the counterfeit is dis tinguished by its peeling off, which the other never does. Sec M. B. Valentini Museum Museorum, &c. p. 439. Hay's Synopsis, !pent. Quadr. p. 63. Wil loughby's lehthyol. and I'allas's Travels. See also our article A STRACAN.