Whole Mimosa Hostilis Root Bark (Chips and Strips)
Botanical use only
$32.501/4 lb
The vocabulary is small and most of it is old. Mordant, scour, WOF, exhaust bath, modifier, fastness, protein and cellulose fibre, tannin, substantive and adjective dyes — twenty terms cover nearly every instruction you will read, and knowing them makes older books usable.
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Natural dyeing instructions are often written in terms nobody defines, because the books assume a teacher. Here they are in plain language.
| Term | What it means |
|---|---|
| Mordant | A mineral salt, usually alum, that bonds fibre and colour so it stays. From the Latin for "to bite". |
| Scour | Washing fibre before mordanting, to remove grease, oil and sizing. |
| WOF | Weight of fibre — the dry weight everything else is a percentage of. |
| Dye bath | The liquid holding the colour, with the plant material strained out or bagged. |
| Exhaust bath | The second or third bath from material already used once. Lighter each time. |
| Modifier | Something added after dyeing to shift the shade: iron, an alkali, an acid. |
| Fastness | How well colour survives light and washing. Two separate properties. |
| Term | What it means |
|---|---|
| Protein fibre | From animals: wool, silk, alpaca, mohair. Takes this colour deeply. |
| Cellulose fibre | From plants: cotton, linen, hemp. Needs a tannin step as well as alum. |
| Skein | A loosely wound loop of yarn, tied in several places so it cannot tangle in the pot. |
| Felting | Wool fibres locking together permanently from heat plus agitation. Not reversible. |
| Handle | How a fibre feels. Too much mordant ruins it; people notice before they can name it. |
| Term | What it means |
|---|---|
| Tannin | A group of plant compounds that bind protein and give colour. This bark is rich in them. See what tannins do in a dye bath. |
| Substantive dye | A colour that holds without a mordant. Tannin-rich material is partly substantive. |
| Adjective dye | A colour that needs a mordant. Most plant colours. |
| Overdyeing | Dyeing an already-dyed fibre a second colour to build a third. |
| Shifted | A shade moved by pH or a modifier rather than by the dye itself. |
| Strike | How fast a colour takes hold. Fast strike gives blotches; slow strike gives even colour. |
| Term | What it means |
|---|---|
| Cut | The physical form: powder, shredded, or stripped lengths. |
| Powder | Milled fine. Fast, strong, needs straining. |
| Shredded | Coarse pieces. Slower, easy to strain, re-baths well. |
| Stripped | Whole inner-bark lengths, closest to how it came off the root. |
Two habits make older books usable. First, read every quantity as a percentage of dry fibre weight even when the book gives handfuls. Second, ignore any instruction to boil: older texts say boil freely because they were written for madder and onion skins, and a tannin bark browns where those do not.
Everything described here is raw botanical material sold for dyeing, soap making and craft work. It is not food, it is not a supplement, and it is not for human consumption. Nothing on this page is a recommendation to put any of it in or on a body.
Overdyeing is dyeing one color on top of another. Mimosa hostilis gives rose to plum, so over indigo blue it makes violet and deep purple, over a yellow dye it makes peach, coral and rust, and with iron it turns grey and slate. Dye small samples first, and change only one thing between them.
Sassafras root bark gives warm tan, rose-tan and orange-brown on wool mordanted with alum, and grey-brown with an iron afterbath. Use about a pound of bark to a pound of dry wool. Soak the bark overnight, simmer it gently for an hour, strain, then hold the mordanted wool in the bath just under a simmer for an hour and let it cool there.
Hard water carries calcium and magnesium and usually runs alkaline, and both shift a tannin dye. With Mimosa hostilis the purples drift toward brown and the color looks duller. Iron in well water greys it further. Rainwater or distilled water is the simplest answer; a little white vinegar or citric acid, to bring the bath to about pH 5 or 6, is the next best.
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