Natural Dyes for Fabric, Yarn and Fiber

Natural dyes are colors drawn from plants and insects and fixed onto fiber: wool, silk, alpaca, cotton and linen. Everything here is Earthues, and it covers the whole chain, not the dyestuffs alone: scour, mordant, dye, and the modifiers that shift a finished shade. Most dyes sell by the ounce, cochineal by the 10 gram and alum by the pound, so a test batch costs very little. Start small. Email us before you order if you are not sure what your project needs.

How Natural Dyeing Works: Scour, Mordant, Dye

Scour, mordant, dye, in that order, with a tannin step before the mordant on cotton or linen. Scouring strips the lanolin, spinning oil, wax and sizing that fiber arrives with, and skipping it is the most common reason a skein comes out blotchy. Wool and silk need hot water and a scouring detergent, no agitation and no sudden temperature changes, and silk still in the gum needs degumming first. Cotton and linen take the same plus soda ash, often simmered for an hour.

Choosing a Mordant: Alum, Cream of Tartar and Iron

A mordant is a metal salt that bridges the dye and the fiber, and without one most natural dyes rinse out in the wash and fade in the window. On wool, aluminum potassium sulfate at 10 to 15 percent of fiber weight with 6 to 8 percent cream of tartar is the traditional start. Cream of tartar evens the uptake and keeps wool soft, and it warms the shade, which brightens some dyes but pushes madder and cochineal toward orange, so leave it out when you want the cooler red.

Aluminum triformate does similar work at 5 to 10 percent of fiber weight and a much lower temperature, with no cream of tartar. It is still an aluminum mordant, so on cotton and linen it does not replace the tannin step. Pick one and stay with it while you learn.

Iron is a true mordant, though most dyers reach for it as a modifier. At 1 to 2 percent of fiber weight, as a short afterbath of well under an hour, it saddens color: yellows go olive, reds go plum, tannins go grey to black. Too much, or too long in the pot, harshens wool and leaves wool and cellulose brittle over time. Keep a separate pot and spoon for iron, since a trace dulls pale yellows.

If you need something to dye, our undyed yarn, undyed spinning fiber, wool roving and top and silk fibers all take a mordant once scoured, but cellulose fibers are the exception and want the tannin step below first.

Natural Fabric Dye for Cotton, Linen and Other Plant Fibers

Cotton, linen and hemp do not mordant the way wool does, and this is where most first attempts on fabric go wrong. Cellulose gives aluminum very little to hold onto, so alum alone leaves weak color that washes down. The fix is a tannin bath first: tannic acid extract adds the least color of its own, myrobalan lays down a warm buff undertone, and chestnut, pomegranate and quebracho yellow bring more. Tannin, then alum, and expect plant fiber to read paler than wool.

Natural Dyes from Plants: Roots, Barks, Leaves and Hulls

The ranges below assume alum mordanted wool or silk. Percentage sets most of the depth, but temperature, time, pH and your own water all move it, so keep notes on what you did and sample before you commit.

• Madder extract: madder root color in concentrated form, brick and terracotta through to a clear red. Hold the bath at 140 to 160 F, because anything near a simmer turns it dull and brown. Madder gives fuller reds in calcium rich water, so soft water dyers add a little chalk.
• Weld: the clearest and most lightfast of the traditional yellows, brightest in a neutral to slightly alkaline bath, so a pinch of chalk helps if your water runs acidic. Chamomile and pomegranate give softer yellows and khaki golds, and neither is rated as lightfast as weld.
• Cutch, chestnut and walnut: tan, cinnamon and deep brown. All three carry their own tannin and bond without a mordant, though alum still deepens and evens them, which makes walnut the most forgiving dye to start with. Chestnut alone stays a light golden tan.
• Logwood purple: saturated purple from a small percentage, grey to black with iron. It is strongly pH sensitive, so acid pulls it red and alkali pushes it blue purple. The purple is among the least lightfast colors here, better on a shawl kept in a drawer than a sunlit curtain, while logwood taken to black with iron holds up far better.

Cochineal and Lac, the Insect Reds

Cochineal is an insect dye and its color is carminic acid. On alum mordanted wool or silk it runs crimson through fuchsia to purple depending on pH: cream of tartar warms it toward an orange red, an alkaline afterbath pushes it to magenta and on to purple. True scarlet came from a tin mordant, which we do not carry. Lac is the other insect red, a deeper dark crimson leaning more brick than cochineal, and it shifts with pH the same way.

Indigo Dye Is a Vat Dye, Not a Mordant Dye

Indigo dye does not behave like anything else here. It will not dissolve in water, so it cannot be mordanted on. A vat reduces it into a soluble form, which is why you need soda ash for alkalinity and a reducing agent such as thiourea dioxide, kept warm rather than hot, around 100 to 120 F. Alkalinity is where wool and silk get hurt, so aim for pH 9 to 9.5 on wool and 10 to 11 on silk, and save the strongest, hottest vats for cotton and linen.

Fiber comes out yellow green and turns blue in the air while you watch. Short repeated dips build a deeper blue than one long soak, and each dip has to oxidize fully before the next. The vat wants to sit still, because stirred in air undoes the reduction. Rinse and wash well, since loose surface indigo is what rubs off. Indigo needs no mordant, and the Earthues Indigo Kit is worth a look before you buy the pieces separately.

How Much to Buy: Weight of Fiber

Every quantity is a percentage of your fiber's dry weight, written as WOF: on 100 grams of dry wool, 5 percent means 5 grams of dye. Weigh dry, because a soaked skein can weigh two or three times what it does dry. The extracts here are concentrated, so most shades sit between the low single digits and about 20 percent, while ground myrobalan runs at its own rate and indigo goes by vat strength and dips.

Working Safely

Most of this is dust control and keeping dye gear out of the kitchen. Weigh powders in still, ventilated air with an N95 or better on, and treat cochineal with extra care, because it is a documented respiratory sensitizer.

Dissolving a powder does not make it harmless. Soda ash is caustic in solution, iron in solution is still a poison, and a warm thiourea dioxide vat gives off sulfur smelling fumes, so set a vat up outdoors or with real cross ventilation. Gloves and eye protection stay on after the powder dissolves. Keep iron away from children, and never put a dye pot back into food use.

Not Sure Where to Start

A first order that works: scour liquid, alum, cream of tartar and one forgiving dye. Chestnut, walnut or cutch gives a good brown with very little coaxing and shows you what a substantive dye does alone, and adding weld or madder shows you what the mordant is for. Weld is the yellow to buy when you want the most lightfast one.

The Earthues Natural Dye Instruction Booklet walks through the maker's own method. Paradise Fibers has served the fiber community since 1997, and we run the shop out of a restored bakery in Spokane. Tell us your fiber and the color you want, and we will tell you what we would use.

If you would rather work with synthetic color, our full dye selection carries acid dyes alongside these natural ones.