Scientific American 16, 5.1.1850
BLUE. - Tack the skin around the edges on a flat board, with the wool outside, finely combed, to hang down. Then get a vessel large enough to let the bard and skin flat into it. Fill up this vessel with hot water and put some sulphate of indigo, well stirred, into it, until the water is of the same depth of color as the wool on the skin is desired to be; then invert the board with the wool side of the skin into the indigo liquor, and let it hang in it until it is the color desired. There should be two holes bored through each end of the board, into which should be inserted strings, forming loops; through these loops should be inserted a pole of stick, (an old broom handle will do) which is made to rest upon the top, across the vessel, to keep the skin from the liquor, but to let the liquor dye the wool. A fire should be placed under the vessel, to heat the liquor to any degree. The liquor may be safely allowed to boil, if it is kept from touching the skin. The skin should not be allowed to get wet, but if it does in the washing, it should receive a little alum water to finish, and then the skin be put our to dry. It should be dried in the air - the board being set up endwise, and changes in position from time to time till the wool is dry. It should then be taken from the board, switched with a rod, and it is ready for use.
When the skin is taken from the kettle, the board must be held in the hands, and the wool side of the skin must be rinsed in cold water until all the acid taste is gone. It then should get a dip in the alum liquor. The alum liquor should taste middling strong - but there is no particular quantity used - judgment can easily settle this. The sulphate of indigo is made by dissolving five parts (such as five ounces) by weight, of finely ground Bengal, or Guatamala indigo, in one part of good (mind, good, new) oil of vitroil. The indigo should be added gradually, in a stone ware vessel, and stirred with a hard wood stick. It should not be added gradually, in a stone ware vessel, and stirred with a hard wood stick. It should not be used in less than nine days after it is made, but if hastily required, it may be used in three days. This dye should be about the thickness of good molasses. A very small quantity will dye a deep shade. It does not dye a fast blue, but it answers well enough for sheep skins, and the alum to finish prevents the wool from being wet easily afterwards. The sulphate of indigo should be kept in a covered dish, out of the reach of children, or those who do not know its nature. Skins may be dyed blue, in the common old fashioned way that out farmers dye their wool, in the urine blue vat, only they must do it with the board, as we have directed, or else dye two skins at once, sewing the the two insides together, and dipping them into the liquor, in the same way that morocco dyers do, but this is not a good way for skins, that are intended for door mats. After what we have sair, any farmer may dye his own lamb-skin door mats blue.
GREEN. - The skin is to be fixed and treated exactrly as directed before, and to the blue liquor in the vessel, some strong fustic liquor is to be added. Fustic is a dye stuff found at all the druggists. It requires a great quantity of it to make of it to make a good green. It should be boiled in a separate vessel and the strong liquor added to the insigo liquor. A small piece of alum, about the size of a pullet's egg, ahould also be added. The color of the liquor will be the guide for the color desired upon the wool of the skin. Do not let it be too dark, for you cannot easily make it light again, but you can make it to the very shade you like, by taking time, and adding a little of the dye-drugs (the indigo and fustic) from time to time - all that has to be done is to lift the skin, and set it carefully back again. To deepen the yellow of the green, some people use turmeric (another yellow dye-drug) along with the fustic, but its color is so fugitive, that if the sun looks at it, its existence terminates. We would not use it. We will give the receipts for all the other colors in future numbers, rendering them so plain, that "he who runneth may read," and there is no one of our subscribers but who, if not at present, may at some future time, want to use them. What we give we warrant correct, without the possibility of a failure, merely remarking, that the wool must be perfectly free from dirt and grease before it is dyed. The sulphate of indigo must be made with care. If teh vitriol is good and new, and the indigo good, anybody, without failure, can make it, and every farmer should have it in his house, for it will dye ribbons and green silk, bombazine and merino frocks for his daughters.