some of the natural colors, when properly produced, are as fast to light and washing as the best of the modern synthetic dyes.
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brown dyes and tannins are found in many trees and plants. tannins are organic acid which can act as a bridge between the mordants, inorganic metal salts and the organic fibres. these are widely utilized in the curing of animal hides (tanning) and are an essential ingredient in preparing cotton cloths for dyeing. |
visible tannins in oak bark |
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Catechu, a resin obtained from boiling chips of the wood of several tropical Acacia trees ( Acacia catechu, A. sundra, Uncaria gambir) contains up to 40% tannins was used much in Indian block printing and calico. the dye was also once produced in Java, Singapore, and Peru. |
Acacia catechu |
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American Black Walnut and butternut (Juglans nigra, J. regia) contain a colorless dye, Juglone. extracted from the green nut hulls, this dye oxidizes to dark brown shades and can be very permanent, dyed with or without mineral fixation. |
dried Walnuthulls |
Allepo-Galls from Turkey |
Quercus robur L., Quercus sp.
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Gallwasp, Biorhizza pallida
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